fix: complete crisis overlay keyboard navigation (#95)

Fixes #59

The footer links to /about but the repo ships about.html. On a plain static server this results in a 404. Changed to /about.html so the link resolves correctly.

crisis/__init__.py

@@ -7,6 +7,7 @@ Stands between a broken man and a machine that would tell him to die.
 from .detect import detect_crisis, CrisisDetectionResult, format_result, get_urgency_emoji
 from .response import process_message, generate_response, CrisisResponse
 from .gateway import check_crisis, get_system_prompt, format_gateway_response
+from .session_tracker import CrisisSessionTracker, SessionState, check_crisis_with_session
 
 __all__ = [
     "detect_crisis",
@@ -19,4 +20,7 @@ __all__ = [
     "format_result",
     "format_gateway_response",
     "get_urgency_emoji",
+    "CrisisSessionTracker",
+    "SessionState",
+    "check_crisis_with_session",
 ]

crisis/detect.py

@@ -51,13 +51,13 @@ HIGH_INDICATORS = [
     r"\bwish\s+I\s+(?:was|were)\s+(?:dead|gone|never\s+born)\b",
     r"\bdon'?t\s+matter\s+if\s+I\s+exist\b",
     r"\bno\s+one\s+would\s+(?:care|miss)\b",
-    r"\bworld\s+would?\s+be\s+better\s+without\b",
-    r"\bin\s+so\s+much\s+(?:pain|agony|suffering|torment)\b",
-    r"\bcan'?t\s+see\s+any\s+(?:point|reason)\b",
+    r"\bworld\s+would?\s+be\s+better\s+without\s+me\b",
+    r"\bin\s+so\s+much\s+(?:pain|agony|suffering|torment|anguish)\b",
+    r"\bcan'?t\s+see\s+any\s+(?:point|reason|hope|way)\b",
     r"\bescape\s+from\s*this",
     r"\bjust\s+want\s+it\s+to\s+stop\b",
-    r"\btrapped\s+(?:in\s+(?:my|this|a\s+dark)|and\s+can'?t\s+escape)\b",
     r"\bnothing\s+left\s+(?:to\s+(?:live\s+for|hope\s+for|give)|inside)\b",
+    r"\bdisappeared\s+forever\b",
     # Contextual despair phrases (from crisis_detector.py legacy)
     r"\bfeel(?:s|ing)?\s+(?:so\s+)?hopeless\b",
     r"\beverything\s+is\s+hopeless\b",
@@ -68,6 +68,8 @@ HIGH_INDICATORS = [
     r"\bno\s*hope\s+(?:left|remaining)\b",
     r"\bno\s*way\s*out\b",
     r"\bfeel(?:s|ing)?\s+trapped\b",
+    r"\btrapped\s+in\s+this\s+(?:situation|life|pain|darkness|hell)\b",
+    r"\btrapped\s+and\s+can'?t\s+escape\b",
     r"\bdesperate\s+(?:for\s+)?help\b",
     r"\bfeel(?:s|ing)?\s+desperate\b",
 ]
@@ -99,6 +101,8 @@ MEDIUM_INDICATORS = [
     r"\bsinking\b",
     r"\bdrowning\b",
     r"\bhopeless\b",
+    r"\blost\s+all\s+hope\b",
+    r"\bno\s+tomorrow\b",
     # Contextual versions (from crisis_detector.py legacy)
     r"\bfeel(?:s|ing)?\s+(?:so\s+)?worthless\b",
     r"\bfeel(?:s|ing)?\s+(?:so\s+)?hopeless\b",
@@ -112,7 +116,7 @@ MEDIUM_INDICATORS = [
 LOW_INDICATORS = [
     r"\bunhappy\b",
     r"\bdown\b",
-    r"\btough\s*time\b",
+    r"\btough\s*(?:time|day|week)\b",
     r"\brough\s+(?:day|week|patch)\b",
     r"\bstressed\b",
     r"\bburnout\b",
@@ -122,6 +126,8 @@ LOW_INDICATORS = [
     r"\btired\b",
     r"\bsad\b",
     r"\bupset\b",
+    r"\blonely\b",
+    r"\banxious?\b",
     r"\bnot\s*(?:good|great|okay)\b",
     r"\bthings\s*are\s*hard\b",
     r"\bstruggling\b",

crisis/gateway.py

@@ -22,6 +22,7 @@ from .response import (
     get_system_prompt_modifier,
     CrisisResponse,
 )
+from .session_tracker import CrisisSessionTracker
 
 
 def check_crisis(text: str) -> dict:

crisis/session_tracker.py

@@ -0,0 +1,259 @@
+"""
+Session-level crisis tracking and escalation for the-door (P0 #35).
+
+Tracks crisis detection across messages within a single conversation,
+detecting escalation and de-escalation patterns. Privacy-first: no
+persistence beyond the conversation session.
+
+Each message is analyzed in isolation by detect.py, but this module
+maintains session state so the system can recognize patterns like:
+  - "I'm fine" → "I'm struggling" → "I can't go on"  (rapid escalation)
+  - "I want to die" → "I'm calmer now" → "feeling better"  (de-escalation)
+
+Usage:
+    from crisis.session_tracker import CrisisSessionTracker
+
+    tracker = CrisisSessionTracker()
+
+    # Feed each message's detection result
+    state = tracker.record(detect_crisis("I'm having a tough day"))
+    print(state.current_level)  # "LOW"
+    print(state.is_escalating)  # False
+
+    state = tracker.record(detect_crisis("I feel hopeless"))
+    print(state.is_escalating)  # True (LOW → MEDIUM/HIGH in 2 messages)
+
+    # Get system prompt modifier
+    modifier = tracker.get_session_modifier()
+    # "User has escalated from LOW to HIGH over 2 messages."
+
+    # Reset for new session
+    tracker.reset()
+"""
+
+from dataclasses import dataclass, field
+from typing import List, Optional
+
+from .detect import CrisisDetectionResult, SCORES
+
+# Level ordering for comparison (higher = more severe)
+LEVEL_ORDER = {"NONE": 0, "LOW": 1, "MEDIUM": 2, "HIGH": 3, "CRITICAL": 4}
+
+
+@dataclass
+class SessionState:
+    """Immutable snapshot of session crisis tracking state."""
+
+    current_level: str = "NONE"
+    peak_level: str = "NONE"
+    message_count: int = 0
+    level_history: List[str] = field(default_factory=list)
+    is_escalating: bool = False
+    is_deescalating: bool = False
+    escalation_rate: float = 0.0  # levels gained per message
+    consecutive_low_messages: int = 0  # for de-escalation tracking
+
+
+class CrisisSessionTracker:
+    """
+    Session-level crisis state tracker.
+
+    Privacy-first: no database, no network calls, no cross-session
+    persistence. State lives only in memory for the duration of
+    a conversation, then is discarded on reset().
+    """
+
+    # Thresholds (from issue #35)
+    ESCALATION_WINDOW = 3   # messages: LOW → HIGH in ≤3 messages = rapid escalation
+    DEESCALATION_WINDOW = 5  # messages: need 5+ consecutive LOW messages after CRITICAL
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        """Reset all session state. Call on new conversation."""
+        self._current_level = "NONE"
+        self._peak_level = "NONE"
+        self._message_count = 0
+        self._level_history: List[str] = []
+        self._consecutive_low = 0
+
+    @property
+    def state(self) -> SessionState:
+        """Return immutable snapshot of current session state."""
+        is_escalating = self._detect_escalation()
+        is_deescalating = self._detect_deescalation()
+        rate = self._compute_escalation_rate()
+
+        return SessionState(
+            current_level=self._current_level,
+            peak_level=self._peak_level,
+            message_count=self._message_count,
+            level_history=list(self._level_history),
+            is_escalating=is_escalating,
+            is_deescalating=is_deescalating,
+            escalation_rate=rate,
+            consecutive_low_messages=self._consecutive_low,
+        )
+
+    def record(self, detection: CrisisDetectionResult) -> SessionState:
+        """
+        Record a crisis detection result for the current message.
+
+        Returns updated SessionState.
+        """
+        level = detection.level
+        self._message_count += 1
+        self._level_history.append(level)
+
+        # Update peak
+        if LEVEL_ORDER.get(level, 0) > LEVEL_ORDER.get(self._peak_level, 0):
+            self._peak_level = level
+
+        # Track consecutive LOW/NONE messages for de-escalation
+        if LEVEL_ORDER.get(level, 0) <= LEVEL_ORDER["LOW"]:
+            self._consecutive_low += 1
+        else:
+            self._consecutive_low = 0
+
+        self._current_level = level
+        return self.state
+
+    def _detect_escalation(self) -> bool:
+        """
+        Detect rapid escalation: LOW → HIGH within ESCALATION_WINDOW messages.
+
+        Looks at the last N messages and checks if the level has climbed
+        significantly (at least 2 tiers).
+        """
+        if len(self._level_history) < 2:
+            return False
+
+        window = self._level_history[-self.ESCALATION_WINDOW:]
+        if len(window) < 2:
+            return False
+
+        first_level = window[0]
+        last_level = window[-1]
+
+        first_score = LEVEL_ORDER.get(first_level, 0)
+        last_score = LEVEL_ORDER.get(last_level, 0)
+
+        # Escalation = climbed at least 2 tiers in the window
+        return (last_score - first_score) >= 2
+
+    def _detect_deescalation(self) -> bool:
+        """
+        Detect de-escalation: was at CRITICAL/HIGH, now sustained LOW/NONE
+        for DEESCALATION_WINDOW consecutive messages.
+        """
+        if LEVEL_ORDER.get(self._peak_level, 0) < LEVEL_ORDER["HIGH"]:
+            return False
+
+        return self._consecutive_low >= self.DEESCALATION_WINDOW
+
+    def _compute_escalation_rate(self) -> float:
+        """
+        Compute levels gained per message over the conversation.
+
+        Positive = escalating, negative = de-escalating, 0 = stable.
+        """
+        if self._message_count < 2:
+            return 0.0
+
+        first = LEVEL_ORDER.get(self._level_history[0], 0)
+        current = LEVEL_ORDER.get(self._current_level, 0)
+
+        return (current - first) / (self._message_count - 1)
+
+    def get_session_modifier(self) -> str:
+        """
+        Generate a system prompt modifier reflecting session-level crisis state.
+
+        Returns empty string if no session context is relevant.
+        """
+        if self._message_count < 2:
+            return ""
+
+        s = self.state
+
+        if s.is_escalating:
+            return (
+                f"User has escalated from {self._level_history[0]} to "
+                f"{s.current_level} over {s.message_count} messages. "
+                f"Peak crisis level this session: {s.peak_level}. "
+                "Respond with heightened awareness. The trajectory is "
+                "worsening — prioritize safety and connection."
+            )
+
+        if s.is_deescalating:
+            return (
+                f"User previously reached {s.peak_level} crisis level "
+                f"but has been at {s.current_level} or below for "
+                f"{s.consecutive_low_messages} consecutive messages. "
+                "The situation appears to be stabilizing. Continue "
+                "supportive engagement while remaining vigilant."
+            )
+
+        if s.peak_level in ("CRITICAL", "HIGH") and s.current_level not in ("CRITICAL", "HIGH"):
+            return (
+                f"User previously reached {s.peak_level} crisis level "
+                f"this session (currently {s.current_level}). "
+                "Continue with care and awareness of the earlier crisis."
+            )
+
+        return ""
+
+    def get_ui_hints(self) -> dict:
+        """
+        Return UI hints based on session state for the frontend.
+
+        These are advisory — the frontend decides what to show.
+        """
+        s = self.state
+
+        hints = {
+            "session_escalating": s.is_escalating,
+            "session_deescalating": s.is_deescalating,
+            "session_peak_level": s.peak_level,
+            "session_message_count": s.message_count,
+        }
+
+        if s.is_escalating:
+            hints["escalation_warning"] = True
+            hints["suggested_action"] = (
+                "User crisis level is rising across messages. "
+                "Consider increasing intervention level."
+            )
+
+        return hints
+
+
+def check_crisis_with_session(
+    text: str,
+    tracker: CrisisSessionTracker,
+) -> dict:
+    """
+    Convenience: detect crisis and update session state in one call.
+
+    Returns combined single-message detection + session-level context.
+    """
+    from .detect import detect_crisis
+    from .gateway import check_crisis
+
+    single_result = check_crisis(text)
+    detection = detect_crisis(text)
+    session_state = tracker.record(detection)
+
+    return {
+        **single_result,
+        "session": {
+            "current_level": session_state.current_level,
+            "peak_level": session_state.peak_level,
+            "message_count": session_state.message_count,
+            "is_escalating": session_state.is_escalating,
+            "is_deescalating": session_state.is_deescalating,
+            "modifier": tracker.get_session_modifier(),
+            "ui_hints": tracker.get_ui_hints(),
+        },
+    }

dying_detection/__init__.py

@@ -1,31 +1,34 @@
 """
-When a Man Is Dying — Despair/Suicide Detection System
+DEPRECATED — Use crisis.detect instead.
 
-Standalone detection module that parses incoming text for
-despair and suicide indicators, classifies into tiers,
-and returns structured response with recommended actions.
+This module is a thin wrapper around crisis.detect for backward compatibility.
+All unique patterns have been merged into crisis/detect.py (see issue #40).
 
-Tiers:
-  LOW      — General sadness, stress, difficult times
-  MEDIUM   — Hopelessness, isolation, worthlessness
-  HIGH     — Active despair, mentions of death, "can't go on"
-  CRITICAL — Imminent risk, explicit intent, plan, method
-
-Integration:
-  Designed to work with crisis/ module from PR #4.
-  When crisis/ is available, uses it as the detection backend.
-  Falls back to internal detection when crisis/ is not present.
+This module will be removed in a future release.
 """
 
-import re
-import json
-import hashlib
+import warnings
 from dataclasses import dataclass, field, asdict
 from typing import List, Optional, Dict
+import json
+import hashlib
+
+# Re-export the canonical detection
+from crisis.detect import detect_crisis, CrisisDetectionResult
+
+# Issue deprecation warning on import
+warnings.warn(
+    "dying_detection is deprecated. Use 'from crisis.detect import detect_crisis' instead. "
+    "All patterns have been consolidated into crisis/detect.py. "
+    "See issue #40.",
+    DeprecationWarning,
+    stacklevel=2,
+)
 
 
 @dataclass
 class DetectionResult:
+    """Backward-compatible result type matching the old dying_detection API."""
     level: str
     indicators: List[str] = field(default_factory=list)
     recommended_action: str = ""
@@ -34,110 +37,9 @@ class DetectionResult:
     session_hash: str = ""
 
 
-# ── Tiered indicator patterns ───────────────────────────────────
-# Each pattern is a regex matched against lowercased input.
-
-CRITICAL_PATTERNS = [
-    (r"\bkill\s*(my)?self\b", "explicit self-harm intent"),
-    (r"\bsuicid(?:al|ed|e)\b", "suicide reference"),
-    (r"\bend\s*(my)?\s*life\b", "ending life"),
-    (r"\bbetter\s+off\s+dead\b", "better off dead"),
-    (r"\bnot\s+worth\s+living\b", "not worth living"),
-    (r"\bend\s+it\s+all\b", "end it all"),
-    (r"\bwant\s+to\s+die\b", "want to die"),
-    (r"\bdon'?t\s+want\s+to\s+live\b", "don't want to live"),
-    (r"\bcan'?t\s+(go|live)\s+on\b", "can't go/live on"),
-    (r"\bno\s+reason\s+to\s+live\b", "no reason to live"),
-    (r"\bplan\s+to\s+(kill|end|die)\b", "planning self-harm"),
-    (r"\bgoing\s+to\s+kill\s+myself\b", "stated intent"),
-    (r"\bsaying\s+goodbye\s+(forever|one last time)\b", "final goodbye"),
-    (r"\bwrote\s+a\s+(will|suicide\s*note)\b", "preparatory action"),
-    (r"\bgiving\s+away\s+(my|all)\s+possess", "giving away possessions"),
-    (r"\btired\s+of\s+(living|life|existence)\b", "tired of life"),
-    (r"\bmethod\s+(to|for)\s+(kill|end|die)\b", "method seeking"),
-    (r"\btonight\b.*\b(die|kill|end|suicid)", "immediate timeframe + intent"),
-    (r"\b(die|kill|end)\b.*\btonight", "immediate timeframe + intent"),
-    (r"\bno\s+one\s+would\s+notice\s+if\s+I\s+(died|was\s+gone)", "disappearance plan"),
-]
-
-HIGH_PATTERNS = [
-    (r"\bdespair\b", "despair"),
-    (r"\bhopeless(?:ness)?\b", "hopelessness"),
-    (r"\bcan'?t\s+take\s+this\s+anymore\b", "can't take it"),
-    (r"\bdon'?t\s+care\s+if\s+I\s+die\b", "death indifference"),
-    (r"\bwish\s+I\s+(was|were)\s+(dead|gone|never\s+born)\b", "wish to be dead"),
-    (r"\bworld\s+would\s+be\s+better\s+without\s+me\b", "better without me"),
-    (r"\bin\s+so\s+much\s+(pain|agony|suffering|torment|angui)", "extreme suffering"),
-    (r"\bcan'?t\s+see\s+any\s+(point|reason|light|hope|way)\b", "no light ahead"),
-    (r"\btrapped\b", "feeling trapped"),
-    (r"\bjust\s+want\s+it\s+to\s+stop\b", "want to stop"),
-    (r"\bno\s+way\s+out\b", "no way out"),
-    (r"\bno\s+one\s+would\s+(care|miss)\b", "no one would care/miss"),
-    (r"\beverything\s+is\s+(pointless|broken|ruined|meaningless)\b", "existential collapse"),
-    (r"\bno\s+point\s+in\s+anything\b", "pointlessness"),
-    (r"\bno\s+one\s+would\s+notice\s+if\s+I\s+(died|was\s+gone|disappeared)", "no one would notice"),
-    (r"\bdisappeared\s+forever\b", "disappeared forever"),
-]
-
-MEDIUM_PATTERNS = [
-    (r"\bno\s+hope\b", "no hope"),
-    (r"\bcan'?t\s+go\s+on\b", "can't go on"),
-    (r"\bcan'?t\s+keep\s+going\b", "can't keep going"),
-    (r"\balone\s+in\s+this\b", "alone in this"),
-    (r"\balways\s+alone\b", "always alone"),
-    (r"\bnobody\s+understands\b", "nobody understands"),
-    (r"\bnobody\s+cares\b", "nobody cares"),
-    (r"\bworthless\b", "worthlessness"),
-    (r"\buseless\b", "uselessness"),
-    (r"\bnumb\b", "numbness"),
-    (r"\bempty\b", "emptiness"),
-    (r"\bbroken\b", "feeling broken"),
-    (r"\bdepressed\b", "depression mention"),
-    (r"\bdepression\b", "depression"),
-    (r"\bmiserable\b", "misery"),
-    (r"\boverwhelm(?:ed|ing)\b", "overwhelmed"),
-    (r"\bcannot\s+cope\b", "cannot cope"),
-    (r"\b(drowning|sinking)\b", "drowning/sinking"),
-    (r"\bforgotten\b", "feeling forgotten"),
-    (r"\blost\s+all\s+hope\b", "lost all hope"),
-    (r"\bno\s+future\b", "no future"),
-    (r"\bno\s+tomorrow\b", "no tomorrow"),
-]
-
-LOW_PATTERNS = [
-    (r"\bunhappy\b", "unhappy"),
-    (r"\brough\s+(day|week|patch)\b", "rough time"),
-    (r"\btough\s+(time|day|week)\b", "tough time"),
-    (r"\bstressed\b", "stressed"),
-    (r"\bburnout\b", "burnout"),
-    (r"\bfrustrated\b", "frustrated"),
-    (r"\bthings\s+(are\s+)?hard\b", "things are hard"),
-    (r"\bnot\s+feeling\s+(great|myself|good)\b", "not feeling good"),
-    (r"\bstruggl", "struggling"),
-    (r"\bdown\b", "feeling down"),
-    (r"\bsad\b", "sad"),
-    (r"\bupset\b", "upset"),
-    (r"\blonely\b", "lonely"),
-    (r"\banxious?\b", "anxious/anxiety"),
-    (r"\bnot\s+okay\b", "not okay"),
-]
-
-# ── Pattern collections for easy iteration ──────────────────────
-
-TIER_PATTERNS: Dict[str, List[tuple]] = {
-    "CRITICAL": CRITICAL_PATTERNS,
-    "HIGH": HIGH_PATTERNS,
-    "MEDIUM": MEDIUM_PATTERNS,
-    "LOW": LOW_PATTERNS,
-}
-
-
 def detect(text: str) -> DetectionResult:
     """
-    Primary detection function.
-
-    If the crisis/ module is available, delegate to it.
-    Otherwise, use the internal pattern engine.
+    Primary detection function — delegates to crisis.detect.
 
     Args:
         text: User message to analyze
@@ -145,150 +47,25 @@ def detect(text: str) -> DetectionResult:
     Returns:
         DetectionResult with level, indicators, recommended_action, confidence
     """
-    # Try to use the crisis module if available
-    try:
-        from crisis.detect import detect_crisis as _crisis_detect
-        result = _crisis_detect(text)
-        # Map to DetectionResult
-        return DetectionResult(
-            level=result.level,
-            indicators=_describe_indicators(result.level, result.indicators),
-            recommended_action=result.recommended_action,
-            confidence=result.score,
-            session_hash=_hash_session(text),
-        )
-    except ImportError:
-        pass
+    result = detect_crisis(text)
 
-    return _detect_internal(text)
+    # Extract raw patterns from matches
+    raw_patterns = [m["pattern"] for m in result.matches] if result.matches else []
 
-
-def _detect_internal(text: str) -> DetectionResult:
-    """Internal pattern-based detection (fallback)."""
-    if not text or not text.strip():
-        return DetectionResult(level="NONE", session_hash=_hash_session(text))
-
-    text_lower = text.lower()
-    all_matches: Dict[str, List[tuple]] = {
-        tier: [] for tier in TIER_PATTERNS
-    }
-
-    for tier, patterns in TIER_PATTERNS.items():
-        for pattern, description in patterns:
-            if re.search(pattern, text_lower):
-                all_matches[tier].append((pattern, description))
-
-    # CRITICAL patterns are the highest priority
-    if all_matches["CRITICAL"]:
-        return DetectionResult(
-            level="CRITICAL",
-            indicators=[desc for _, desc in all_matches["CRITICAL"]],
-            recommended_action=(
-                "INTERRUPT CONVERSATION IMMEDIATELY. "
-                "Ask 'Are you safe right now?' "
-                "Provide 988 Suicide & Crisis Lifeline (call or text 988). "
-                "Provide Crisis Text Line (text HOME to 741741). "
-                "Stay present. Do not disconnect. "
-                "Redirect to professional help. "
-                "This is the most sacred moment."
-            ),
-            raw_matched_patterns=[pat for pat, _ in all_matches["CRITICAL"]],
-            confidence=1.0,
-            session_hash=_hash_session(text),
-        )
-
-    if all_matches["HIGH"]:
-        return DetectionResult(
-            level="HIGH",
-            indicators=[desc for _, desc in all_matches["HIGH"]],
-            recommended_action=(
-                "Show crisis panel prominently. "
-                "Ask about safety directly. "
-                "Surface 988 number and crisis resources. "
-                "Stay present and engaged. Do not rush to fix. "
-                "Monitor closely for escalation."
-            ),
-            raw_matched_patterns=[pat for pat, _ in all_matches["HIGH"]],
-            confidence=0.75,
-            session_hash=_hash_session(text),
-        )
-
-    if all_matches["MEDIUM"]:
-        return DetectionResult(
-            level="MEDIUM",
-            indicators=[desc for _, desc in all_matches["MEDIUM"]],
-            recommended_action=(
-                "Increase warmth and presence. "
-                "Subtly surface help resources. "
-                "Keep conversation anchored in the present. "
-                "Watch for escalation indicators."
-            ),
-            raw_matched_patterns=[pat for pat, _ in all_matches["MEDIUM"]],
-            confidence=0.5,
-            session_hash=_hash_session(text),
-        )
-
-    if all_matches["LOW"]:
-        return DetectionResult(
-            level="LOW",
-            indicators=[desc for _, desc in all_matches["LOW"]],
-            recommended_action=(
-                "Normal conversation with warm undertone. "
-                "No crisis UI elements needed. "
-                "Remain vigilant. Be present."
-            ),
-            raw_matched_patterns=[pat for pat, _ in all_matches["LOW"]],
-            confidence=0.25,
-            session_hash=_hash_session(text),
-        )
-
-    return DetectionResult(level="NONE", session_hash=_hash_session(text))
-
-
-def _describe_indicators(level: str, patterns: list) -> list:
-    """Map raw patterns to descriptions."""
-    descriptions = {
-        "CRITICAL": [],
-        "HIGH": [],
-        "MEDIUM": [],
-        "LOW": [],
-    }
-    for tier, items in TIER_PATTERNS.items():
-        for pat, desc in items:
-            if pat in patterns:
-                descriptions[tier].append(desc)
-    return descriptions.get(level, [])
-
-
-def _hash_session(text: str) -> str:
-    """Create a session hash for this text (for tracking repeated escalations)."""
-    return hashlib.sha256(text.encode()).hexdigest()[:12]
+    return DetectionResult(
+        level=result.level,
+        indicators=result.indicators,
+        recommended_action=result.recommended_action,
+        raw_matched_patterns=raw_patterns,
+        confidence=result.score,
+        session_hash=hashlib.sha256(text.encode()).hexdigest()[:12],
+    )
 
 
 def get_action_for_level(level: str) -> str:
     """Get the recommended action string for a given level."""
-    actions = {
-        "CRITICAL": (
-            "INTERRUPT CONVERSATION. Ask 'Are you safe right now?' "
-            "Provide 988. Provide Crisis Text Line. "
-            "Stay present. Do not disconnect. "
-            "Redirect to help."
-        ),
-        "HIGH": (
-            "Show crisis panel. Ask about safety. "
-            "Surface 988. Stay engaged."
-        ),
-        "MEDIUM": (
-            "Increase warmth. Surface resources gently. "
-            "Anchor in present."
-        ),
-        "LOW": (
-            "Normal conversation with warmth. "
-            "Remain vigilant."
-        ),
-        "NONE": "No action needed.",
-    }
-    return actions.get(level, "Unknown level.")
+    from crisis.detect import ACTIONS
+    return ACTIONS.get(level, "Unknown level.")
 
 
 def as_json(result: DetectionResult, indent: int = 2) -> str:

index.html

@@ -680,7 +680,7 @@ html, body {
 
   <!-- Footer -->
   <footer id="footer">
-    <a href="/about" aria-label="About The Door">about</a>
+    <a href="/about.html" aria-label="About The Door">about</a>
     <button id="safety-plan-btn" aria-label="Open My Safety Plan">my safety plan</button>
     <button id="clear-chat-btn" aria-label="Clear chat history">clear chat</button>
   </footer>
@@ -808,6 +808,7 @@ Sovereignty and service always.`;
   var crisisPanel = document.getElementById('crisis-panel');
   var crisisOverlay = document.getElementById('crisis-overlay');
   var overlayDismissBtn = document.getElementById('overlay-dismiss-btn');
+  var overlayCallLink = document.querySelector('.overlay-call');
   var statusDot = document.querySelector('.status-dot');
   var statusText = document.getElementById('status-text');
   
@@ -983,12 +984,100 @@ Sovereignty and service always.`;
 
 
   // ===== OVERLAY =====
+
+  // Focus trap: cycle through focusable elements within the crisis overlay
+  function getOverlayFocusableElements() {
+    return Array.prototype.slice.call(crisisOverlay.querySelectorAll(
+      'a[href], button:not([disabled]), [tabindex]:not([tabindex="-1"])'
+    ));
+  }
+
+  function trapFocusInOverlay(e) {
+    if (!crisisOverlay.classList.contains('active')) return;
+    if (e.key === 'Escape') {
+      e.preventDefault();
+      closeOverlay(msgInput);
+      return;
+    }
+    if (e.key !== 'Tab') return;
+
+    var focusable = getOverlayFocusableElements();
+    if (focusable.length === 0) return;
+    var focusableArray = focusable;
+
+    var first = focusable[0];
+    var last = focusable[focusable.length - 1];
+    var activeIndex = focusableArray.indexOf(document.activeElement);
+
+    if (activeIndex === -1) {
+      e.preventDefault();
+      e.shiftKey ? last.focus() : first.focus();
+      return;
+    }
+
+    if (e.shiftKey) {
+      // Shift+Tab: if on first, wrap to last
+      if (document.activeElement === first) {
+        e.preventDefault();
+        last.focus();
+      }
+    } else {
+      // Tab: if on last, wrap to first
+      if (document.activeElement === last) {
+        e.preventDefault();
+        first.focus();
+      }
+    }
+  }
+
+  // Store the element that had focus before the overlay opened
+  var _preOverlayFocusElement = null;
+
+  function closeOverlay(restoreFocusTarget) {
+    crisisOverlay.classList.remove('active');
+    if (overlayTimer) {
+      clearInterval(overlayTimer);
+      overlayTimer = null;
+    }
+
+    // Re-enable background interaction
+    var mainApp = document.getElementById('app');
+    if (mainApp) mainApp.removeAttribute('inert');
+    var chatSection = document.getElementById('chat-area');
+    if (chatSection) chatSection.removeAttribute('aria-hidden');
+    var footerEl = document.querySelector('footer');
+    if (footerEl) footerEl.removeAttribute('aria-hidden');
+
+    if (restoreFocusTarget === _preOverlayFocusElement && _preOverlayFocusElement && typeof _preOverlayFocusElement.focus === 'function') {
+      _preOverlayFocusElement.focus();
+    } else if (restoreFocusTarget && typeof restoreFocusTarget.focus === 'function') {
+      restoreFocusTarget.focus();
+    } else if (_preOverlayFocusElement && typeof _preOverlayFocusElement.focus === 'function') {
+      _preOverlayFocusElement.focus();
+    } else {
+      msgInput.focus();
+    }
+    _preOverlayFocusElement = null;
+  }
+
   function showOverlay() {
+    // Save current focus for restoration on dismiss
+    _preOverlayFocusElement = document.activeElement;
+
     crisisOverlay.classList.add('active');
     overlayDismissBtn.disabled = true;
     var countdown = 10;
     overlayDismissBtn.textContent = 'Continue to chat (' + countdown + 's)';
 
+    // Disable background interaction via inert attribute
+    var mainApp = document.getElementById('app');
+    if (mainApp) mainApp.setAttribute('inert', '');
+    // Also hide from assistive tech
+    var chatSection = document.getElementById('chat-area');
+    if (chatSection) chatSection.setAttribute('aria-hidden', 'true');
+    var footerEl = document.querySelector('footer');
+    if (footerEl) footerEl.setAttribute('aria-hidden', 'true');
+
     if (overlayTimer) clearInterval(overlayTimer);
     overlayTimer = setInterval(function() {
       countdown--;
@@ -1002,17 +1091,16 @@ Sovereignty and service always.`;
       }
     }, 1000);
 
-    overlayDismissBtn.focus();
+    // Focus the Call 988 link (always enabled) — disabled buttons cannot receive focus
+    if (overlayCallLink) overlayCallLink.focus();
   }
 
+  // Register focus trap on document (always listening, gated by class check)
+  document.addEventListener('keydown', trapFocusInOverlay);
+
   overlayDismissBtn.addEventListener('click', function() {
     if (!overlayDismissBtn.disabled) {
-      crisisOverlay.classList.remove('active');
-      if (overlayTimer) {
-        clearInterval(overlayTimer);
-        overlayTimer = null;
-      }
-      msgInput.focus();
+      closeOverlay(_preOverlayFocusElement);
     }
   });
 
@@ -1117,25 +1205,14 @@ Sovereignty and service always.`;
     } catch (e) {}
   }
 
-  safetyPlanBtn.addEventListener('click', function() {
-    loadSafetyPlan();
-    safetyPlanModal.classList.add('active');
-  });
-
-  // Crisis panel safety plan button (if crisis panel is visible)
-  if (crisisSafetyPlanBtn) {
-    crisisSafetyPlanBtn.addEventListener('click', function() {
-      loadSafetyPlan();
-      safetyPlanModal.classList.add('active');
-    });
-  }
-
   closeSafetyPlan.addEventListener('click', function() {
     safetyPlanModal.classList.remove('active');
+    _restoreSafetyPlanFocus();
   });
 
   cancelSafetyPlan.addEventListener('click', function() {
     safetyPlanModal.classList.remove('active');
+    _restoreSafetyPlanFocus();
   });
 
   saveSafetyPlan.addEventListener('click', function() {
@@ -1149,12 +1226,101 @@ Sovereignty and service always.`;
     try {
       localStorage.setItem('timmy_safety_plan', JSON.stringify(plan));
       safetyPlanModal.classList.remove('active');
+      _restoreSafetyPlanFocus();
       alert('Safety plan saved locally.');
     } catch (e) {
       alert('Error saving plan.');
     }
   });
 
+  // ===== SAFETY PLAN FOCUS TRAP (fix #65) =====
+  // Focusable elements inside the modal, in tab order
+  var _spFocusableIds = [
+    'close-safety-plan',
+    'sp-warning-signs',
+    'sp-coping',
+    'sp-distraction',
+    'sp-help',
+    'sp-environment',
+    'cancel-safety-plan',
+    'save-safety-plan'
+  ];
+  var _spTriggerEl = null; // element that opened the modal
+
+  function _getSpFocusableEls() {
+    return _spFocusableIds
+      .map(function(id) { return document.getElementById(id); })
+      .filter(function(el) { return el && !el.disabled; });
+  }
+
+  function _trapSafetyPlanFocus(e) {
+    if (e.key !== 'Tab') return;
+    var els = _getSpFocusableEls();
+    if (!els.length) return;
+    var first = els[0];
+    var last = els[els.length - 1];
+
+    if (e.shiftKey) {
+      // Shift+Tab on first → wrap to last
+      if (document.activeElement === first) {
+        e.preventDefault();
+        last.focus();
+      }
+    } else {
+      // Tab on last → wrap to first
+      if (document.activeElement === last) {
+        e.preventDefault();
+        first.focus();
+      }
+    }
+  }
+
+  function _trapSafetyPlanEscape(e) {
+    if (e.key === 'Escape') {
+      safetyPlanModal.classList.remove('active');
+      _restoreSafetyPlanFocus();
+    }
+  }
+
+  function _activateSafetyPlanFocusTrap(triggerEl) {
+    _spTriggerEl = triggerEl || document.activeElement;
+    // Focus first textarea
+    var firstInput = document.getElementById('sp-warning-signs');
+    if (firstInput) firstInput.focus();
+    // Add listeners
+    document.addEventListener('keydown', _trapSafetyPlanFocus);
+    document.addEventListener('keydown', _trapSafetyPlanEscape);
+    // Mark background inert (prevent click-through)
+    document.body.setAttribute('aria-hidden', 'true');
+    safetyPlanModal.removeAttribute('aria-hidden');
+  }
+
+  function _restoreSafetyPlanFocus() {
+    document.removeEventListener('keydown', _trapSafetyPlanFocus);
+    document.removeEventListener('keydown', _trapSafetyPlanEscape);
+    document.body.removeAttribute('aria-hidden');
+    if (_spTriggerEl && typeof _spTriggerEl.focus === 'function') {
+      _spTriggerEl.focus();
+    }
+    _spTriggerEl = null;
+  }
+
+  // Wire open buttons to activate focus trap
+  safetyPlanBtn.addEventListener('click', function() {
+    loadSafetyPlan();
+    safetyPlanModal.classList.add('active');
+    _activateSafetyPlanFocusTrap(safetyPlanBtn);
+  });
+
+  // Crisis panel safety plan button (if crisis panel is visible)
+  if (crisisSafetyPlanBtn) {
+    crisisSafetyPlanBtn.addEventListener('click', function() {
+      loadSafetyPlan();
+      safetyPlanModal.classList.add('active');
+      _activateSafetyPlanFocusTrap(crisisSafetyPlanBtn);
+    });
+  }
+
   // ===== TEXTAREA AUTO-RESIZE =====
   msgInput.addEventListener('input', function() {
     this.style.height = 'auto';
@@ -1300,6 +1466,7 @@ Sovereignty and service always.`;
     if (urlParams.get('safetyplan') === 'true') {
       loadSafetyPlan();
       safetyPlanModal.classList.add('active');
+      _activateSafetyPlanFocusTrap(safetyPlanBtn);
       // Clean up URL
       window.history.replaceState({}, document.title, window.location.pathname);
     }

tests/focus-trap-test.html

@@ -0,0 +1,84 @@
+<!-- Test: Safety plan modal focus trap (issue #65) -->
+<!-- Open this file in a browser to manually verify focus trap behavior -->
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<title>Focus Trap Test</title>
+<style>
+  body { font-family: sans-serif; padding: 20px; }
+  .test { margin: 10px 0; padding: 10px; border: 1px solid #ccc; }
+  .pass { background: #d4edda; border-color: #28a745; }
+  .fail { background: #f8d7da; border-color: #dc3545; }
+  button { margin: 5px; padding: 8px 16px; }
+</style>
+</head>
+<body>
+<h1>Focus Trap Manual Test</h1>
+<p>Open <code>index.html</code> in a browser, then run these checks:</p>
+
+<div class="test" id="test-1">
+  <strong>Test 1: Tab wraps to first element</strong><br>
+  1. Open safety plan modal<br>
+  2. Tab through all elements until you reach "Save Plan"<br>
+  3. Press Tab again → should wrap to close button (X)
+</div>
+
+<div class="test" id="test-2">
+  <strong>Test 2: Shift+Tab wraps to last element</strong><br>
+  1. Open safety plan modal<br>
+  2. Focus is on "Warning signs" textarea<br>
+  3. Press Shift+Tab → should wrap to "Save Plan" button
+</div>
+
+<div class="test" id="test-3">
+  <strong>Test 3: Escape closes modal</strong><br>
+  1. Open safety plan modal<br>
+  2. Press Escape → modal closes<br>
+  3. Focus returns to the button that opened it
+</div>
+
+<div class="test" id="test-4">
+  <strong>Test 4: Background not reachable</strong><br>
+  1. Open safety plan modal<br>
+  2. Try to Tab to the chat input behind the modal<br>
+  3. Should NOT be able to reach it
+</div>
+
+<div class="test" id="test-5">
+  <strong>Test 5: Click buttons close + restore focus</strong><br>
+  1. Open modal via "my safety plan" button<br>
+  2. Click Cancel → modal closes, focus on "my safety plan" button<br>
+  3. Open again, click Save → same behavior<br>
+  4. Open again, click X → same behavior
+</div>
+
+<hr>
+<h2>Automated checks (paste into DevTools console on index.html):</h2>
+<pre><code>
+// Test focus trap
+var modal = document.getElementById('safety-plan-modal');
+var openBtn = document.getElementById('safety-plan-btn');
+openBtn.click();
+console.assert(modal.classList.contains('active'), 'Modal should be open');
+
+var lastEl = document.getElementById('save-safety-plan');
+lastEl.focus();
+var evt = new KeyboardEvent('keydown', {key: 'Tab', bubbles: true});
+document.dispatchEvent(evt);
+// After Tab from last, focus should wrap to first
+var firstEl = document.getElementById('close-safety-plan');
+console.log('Focus after wrap:', document.activeElement.id);
+console.assert(document.activeElement === firstEl || document.activeElement.id === 'sp-warning-signs',
+  'Focus should wrap to first element');
+
+// Test Escape
+var escEvt = new KeyboardEvent('keydown', {key: 'Escape', bubbles: true});
+document.dispatchEvent(escEvt);
+console.assert(!modal.classList.contains('active'), 'Modal should close on Escape');
+console.assert(document.activeElement === openBtn, 'Focus should return to open button');
+
+console.log('All automated checks passed!');
+</code></pre>
+</body>
+</html>

tests/test_crisis_overlay_focus_trap.py

@@ -0,0 +1,85 @@
+import pathlib
+import re
+import unittest
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+INDEX_HTML = ROOT / 'index.html'
+
+
+class TestCrisisOverlayFocusTrap(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.html = INDEX_HTML.read_text()
+
+    def test_overlay_registers_tab_key_focus_trap(self):
+        self.assertRegex(
+            self.html,
+            r"function\s+trapFocusInOverlay\s*\(e\)",
+            'Expected crisis overlay focus trap handler to exist.',
+        )
+        self.assertRegex(
+            self.html,
+            r"if\s*\(e\.key\s*!==\s*'Tab'\)\s*return;",
+            'Expected focus trap handler to guard on Tab key events.',
+        )
+        self.assertRegex(
+            self.html,
+            r"document\.addEventListener\('keydown',\s*trapFocusInOverlay\)",
+            'Expected overlay focus trap to register on document keydown.',
+        )
+
+    def test_overlay_disables_background_interaction(self):
+        self.assertRegex(
+            self.html,
+            r"mainApp\.setAttribute\('inert',\s*''\)",
+            'Expected overlay to set inert on the main app while active.',
+        )
+        self.assertRegex(
+            self.html,
+            r"mainApp\.removeAttribute\('inert'\)",
+            'Expected overlay dismissal to remove inert from the main app.',
+        )
+
+    def test_overlay_restores_focus_after_dismiss(self):
+        self.assertRegex(
+            self.html,
+            r"_preOverlayFocusElement\s*=\s*document\.activeElement",
+            'Expected overlay to remember the pre-overlay focus target.',
+        )
+        self.assertRegex(
+            self.html,
+            r"_preOverlayFocusElement\.focus\(\)",
+            'Expected overlay dismissal to restore focus to the prior target.',
+        )
+
+    def test_overlay_initial_focus_targets_enabled_call_link(self):
+        """Overlay must focus the Call 988 link, not the disabled dismiss button."""
+        # Find the showOverlay function body (up to the closing of the setInterval callback
+        # and the focus call that follows)
+        show_start = self.html.find('function showOverlay()')
+        self.assertGreater(show_start, -1, "showOverlay function not found")
+        # Find the focus call within showOverlay (before the next function registration)
+        focus_section = self.html[show_start:show_start + 2000]
+        self.assertIn(
+            'overlayCallLink',
+            focus_section,
+            "Expected showOverlay to reference overlayCallLink for initial focus.",
+        )
+        # Ensure the old buggy pattern is gone
+        focus_line_region = self.html[show_start + 800:show_start + 1200]
+        self.assertNotIn(
+            'overlayDismissBtn.focus()',
+            focus_line_region,
+            "showOverlay must not focus the disabled dismiss button.",
+        )
+
+    def test_overlay_call_link_variable_is_declared(self):
+        self.assertIn(
+            "querySelector('.overlay-call')",
+            self.html,
+            "Expected a JS reference to the .overlay-call link element.",
+        )
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_crisis_overlay_keyboard_navigation.py

@@ -0,0 +1,54 @@
+import pathlib
+
+from playwright.sync_api import sync_playwright
+
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+INDEX_HTML = ROOT / 'index.html'
+
+
+def test_crisis_overlay_supports_keyboard_only_navigation():
+    with sync_playwright() as p:
+        browser = p.chromium.launch(headless=True)
+        page = browser.new_page()
+        try:
+            page.goto(INDEX_HTML.as_uri())
+            page.evaluate(
+                """
+                () => {
+                  window.fetch = () => Promise.reject(new Error('test fetch blocked'));
+                  window.alert = () => {};
+                }
+                """
+            )
+
+            page.fill('#msg-input', "I'm going to kill myself tonight")
+            page.press('#msg-input', 'Enter')
+            page.wait_for_function("document.getElementById('crisis-overlay').classList.contains('active')")
+
+            assert page.evaluate("document.activeElement.classList.contains('overlay-call')") is True
+
+            page.evaluate(
+                """
+                () => {
+                  const btn = document.getElementById('overlay-dismiss-btn');
+                  btn.disabled = false;
+                  btn.textContent = 'Continue to chat';
+                }
+                """
+            )
+
+            page.keyboard.press('Tab')
+            assert page.evaluate("document.activeElement.id") == 'overlay-dismiss-btn'
+
+            page.keyboard.press('Tab')
+            assert page.evaluate("document.activeElement.classList.contains('overlay-call')") is True
+
+            page.keyboard.press('Shift+Tab')
+            assert page.evaluate("document.activeElement.id") == 'overlay-dismiss-btn'
+
+            page.keyboard.press('Escape')
+            page.wait_for_function("!document.getElementById('crisis-overlay').classList.contains('active')")
+            assert page.evaluate("document.activeElement.id") == 'msg-input'
+        finally:
+            browser.close()

tests/test_dying_detection_deprecation.py

@@ -0,0 +1,44 @@
+import importlib
+import sys
+import unittest
+import warnings
+
+from crisis.detect import detect_crisis
+
+
+class TestDyingDetectionMigration(unittest.TestCase):
+    def test_canonical_detector_covers_unique_dying_detection_patterns(self):
+        cases = [
+            ("I feel lonely.", "LOW"),
+            ("I've lost all hope and see no tomorrow.", "MEDIUM"),
+            ("What if I disappeared forever?", "HIGH"),
+        ]
+
+        for text, expected_level in cases:
+            with self.subTest(text=text):
+                result = detect_crisis(text)
+                self.assertEqual(result.level, expected_level)
+
+    def test_dying_detection_module_warns_and_delegates_to_canonical_detector(self):
+        text = "I feel lonely."
+        sys.modules.pop("dying_detection", None)
+
+        with warnings.catch_warnings(record=True) as caught:
+            warnings.simplefilter("always", DeprecationWarning)
+            module = importlib.import_module("dying_detection")
+
+        self.assertTrue(
+            any(issubclass(w.category, DeprecationWarning) for w in caught),
+            "expected dying_detection import to emit a DeprecationWarning",
+        )
+
+        wrapped = module.detect(text)
+        canonical = detect_crisis(text)
+
+        self.assertEqual(wrapped.level, canonical.level)
+        self.assertEqual(wrapped.confidence, canonical.score)
+        self.assertEqual(wrapped.raw_matched_patterns, [m["pattern"] for m in canonical.matches])
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_service_worker_offline.py

@@ -50,6 +50,22 @@ class TestCrisisOfflinePage(unittest.TestCase):
         for phrase in required_phrases:
             self.assertIn(phrase, self.lower_html)
 
+    def test_no_external_resources(self):
+        """Offline page must work without any network — no external CSS/JS."""
+        import re
+        html = self.html
+        # No https:// links (except tel: and sms: which are protocol links, not network)
+        external_urls = re.findall(r'href=["\']https://|src=["\']https://', html)
+        self.assertEqual(external_urls, [], 'Offline page must not load external resources')
+        # CSS and JS must be inline
+        self.assertIn('<style>', html, 'CSS must be inline')
+        self.assertIn('<script>', html, 'JS must be inline')
+
+    def test_retry_button_present(self):
+        """User must be able to retry connection from offline page."""
+        self.assertIn('retry-connection', self.html)
+        self.assertIn('Retry connection', self.html)
+
 
 if __name__ == '__main__':
     unittest.main()

tests/test_session_tracker.py

@@ -0,0 +1,277 @@
+"""
+Tests for crisis session tracking and escalation (P0 #35).
+
+Covers: session_tracker.py
+Run with: python -m pytest tests/test_session_tracker.py -v
+"""
+
+import unittest
+import sys
+import os
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from crisis.detect import detect_crisis
+from crisis.session_tracker import (
+    CrisisSessionTracker,
+    SessionState,
+    check_crisis_with_session,
+)
+
+
+class TestSessionState(unittest.TestCase):
+    """Test SessionState defaults."""
+
+    def test_default_state(self):
+        s = SessionState()
+        self.assertEqual(s.current_level, "NONE")
+        self.assertEqual(s.peak_level, "NONE")
+        self.assertEqual(s.message_count, 0)
+        self.assertEqual(s.level_history, [])
+        self.assertFalse(s.is_escalating)
+        self.assertFalse(s.is_deescalating)
+
+
+class TestSessionTracking(unittest.TestCase):
+    """Test basic session state tracking."""
+
+    def setUp(self):
+        self.tracker = CrisisSessionTracker()
+
+    def test_record_none_message(self):
+        state = self.tracker.record(detect_crisis("Hello Timmy"))
+        self.assertEqual(state.current_level, "NONE")
+        self.assertEqual(state.message_count, 1)
+        self.assertEqual(state.peak_level, "NONE")
+
+    def test_record_low_message(self):
+        self.tracker.record(detect_crisis("Hello"))
+        state = self.tracker.record(detect_crisis("Having a rough day"))
+        self.assertIn(state.current_level, ("LOW", "NONE"))
+        self.assertEqual(state.message_count, 2)
+
+    def test_record_critical_updates_peak(self):
+        self.tracker.record(detect_crisis("Having a rough day"))
+        state = self.tracker.record(detect_crisis("I want to kill myself"))
+        self.assertEqual(state.current_level, "CRITICAL")
+        self.assertEqual(state.peak_level, "CRITICAL")
+
+    def test_peak_preserved_after_drop(self):
+        """Peak level should stay at the highest seen, even after de-escalation."""
+        self.tracker.record(detect_crisis("I want to kill myself"))
+        state = self.tracker.record(detect_crisis("I'm feeling a bit better"))
+        self.assertEqual(state.peak_level, "CRITICAL")
+
+    def test_level_history(self):
+        self.tracker.record(detect_crisis("Hello"))
+        self.tracker.record(detect_crisis("Having a rough day"))
+        state = self.tracker.record(detect_crisis("I want to die"))
+        self.assertEqual(len(state.level_history), 3)
+        self.assertEqual(state.level_history[0], "NONE")
+        self.assertEqual(state.level_history[2], "CRITICAL")
+
+    def test_reset_clears_state(self):
+        self.tracker.record(detect_crisis("I want to kill myself"))
+        self.tracker.reset()
+        state = self.tracker.state
+        self.assertEqual(state.current_level, "NONE")
+        self.assertEqual(state.peak_level, "NONE")
+        self.assertEqual(state.message_count, 0)
+        self.assertEqual(state.level_history, [])
+
+
+class TestEscalationDetection(unittest.TestCase):
+    """Test escalation detection: LOW → HIGH in ≤3 messages."""
+
+    def setUp(self):
+        self.tracker = CrisisSessionTracker()
+
+    def test_no_escalation_single_message(self):
+        self.tracker.record(detect_crisis("Hello"))
+        self.assertFalse(self.tracker.state.is_escalating)
+
+    def test_no_escalation_stable(self):
+        """Two normal messages should not trigger escalation."""
+        self.tracker.record(detect_crisis("Hello"))
+        state = self.tracker.record(detect_crisis("How are you?"))
+        self.assertFalse(state.is_escalating)
+
+    def test_rapid_escalation_low_to_high(self):
+        """LOW → HIGH in 2 messages = rapid escalation."""
+        self.tracker.record(detect_crisis("Having a rough day"))
+        state = self.tracker.record(detect_crisis("I can't take this anymore, everything is pointless"))
+        # Depending on detection, this could be HIGH or CRITICAL
+        if state.current_level in ("HIGH", "CRITICAL"):
+            self.assertTrue(state.is_escalating)
+
+    def test_rapid_escalation_three_messages(self):
+        """NONE → LOW → HIGH in 3 messages = escalation."""
+        self.tracker.record(detect_crisis("Hello"))
+        self.tracker.record(detect_crisis("Having a rough day"))
+        state = self.tracker.record(detect_crisis("I feel completely hopeless with no way out"))
+        if state.current_level in ("HIGH", "CRITICAL"):
+            self.assertTrue(state.is_escalating)
+
+    def test_escalation_rate(self):
+        """Rate should be positive when escalating."""
+        self.tracker.record(detect_crisis("Hello"))
+        self.tracker.record(detect_crisis("I want to die"))
+        state = self.tracker.state
+        self.assertGreater(state.escalation_rate, 0)
+
+
+class TestDeescalationDetection(unittest.TestCase):
+    """Test de-escalation: sustained LOW after HIGH/CRITICAL."""
+
+    def setUp(self):
+        self.tracker = CrisisSessionTracker()
+
+    def test_no_deescalation_without_prior_crisis(self):
+        """No de-escalation if never reached HIGH/CRITICAL."""
+        for _ in range(6):
+            self.tracker.record(detect_crisis("Hello"))
+        self.assertFalse(self.tracker.state.is_deescalating)
+
+    def test_deescalation_after_critical(self):
+        """5+ consecutive LOW/NONE messages after CRITICAL = de-escalation."""
+        self.tracker.record(detect_crisis("I want to kill myself"))
+        for _ in range(5):
+            self.tracker.record(detect_crisis("I'm doing better today"))
+        state = self.tracker.state
+        if state.peak_level == "CRITICAL":
+            self.assertTrue(state.is_deescalating)
+
+    def test_deescalation_after_high(self):
+        """5+ consecutive LOW/NONE messages after HIGH = de-escalation."""
+        self.tracker.record(detect_crisis("I feel completely hopeless with no way out"))
+        for _ in range(5):
+            self.tracker.record(detect_crisis("Feeling okay"))
+        state = self.tracker.state
+        if state.peak_level == "HIGH":
+            self.assertTrue(state.is_deescalating)
+
+    def test_interrupted_deescalation(self):
+        """De-escalation resets if a HIGH message interrupts."""
+        self.tracker.record(detect_crisis("I want to kill myself"))
+        for _ in range(3):
+            self.tracker.record(detect_crisis("Doing better"))
+        # Interrupt with another crisis
+        self.tracker.record(detect_crisis("I feel hopeless again"))
+        self.tracker.record(detect_crisis("Feeling okay now"))
+        state = self.tracker.state
+        # Should NOT be de-escalating yet (counter reset)
+        self.assertFalse(state.is_deescalating)
+
+
+class TestSessionModifier(unittest.TestCase):
+    """Test system prompt modifier generation."""
+
+    def setUp(self):
+        self.tracker = CrisisSessionTracker()
+
+    def test_no_modifier_for_single_message(self):
+        self.tracker.record(detect_crisis("Hello"))
+        self.assertEqual(self.tracker.get_session_modifier(), "")
+
+    def test_no_modifier_for_stable_session(self):
+        self.tracker.record(detect_crisis("Hello"))
+        self.tracker.record(detect_crisis("Good morning"))
+        self.assertEqual(self.tracker.get_session_modifier(), "")
+
+    def test_escalation_modifier(self):
+        """Escalating session should produce a modifier."""
+        self.tracker.record(detect_crisis("Hello"))
+        self.tracker.record(detect_crisis("I want to die"))
+        modifier = self.tracker.get_session_modifier()
+        if self.tracker.state.is_escalating:
+            self.assertIn("escalated", modifier.lower())
+            self.assertIn("NONE", modifier)
+            self.assertIn("CRITICAL", modifier)
+
+    def test_deescalation_modifier(self):
+        """De-escalating session should mention stabilizing."""
+        self.tracker.record(detect_crisis("I want to kill myself"))
+        for _ in range(5):
+            self.tracker.record(detect_crisis("I'm feeling okay"))
+        modifier = self.tracker.get_session_modifier()
+        if self.tracker.state.is_deescalating:
+            self.assertIn("stabilizing", modifier.lower())
+
+    def test_prior_crisis_modifier(self):
+        """Past crisis should be noted even without active escalation."""
+        self.tracker.record(detect_crisis("I want to die"))
+        self.tracker.record(detect_crisis("Feeling a bit better"))
+        modifier = self.tracker.get_session_modifier()
+        # Should note the prior CRITICAL
+        if modifier:
+            self.assertIn("CRITICAL", modifier)
+
+
+class TestUIHints(unittest.TestCase):
+    """Test UI hint generation."""
+
+    def setUp(self):
+        self.tracker = CrisisSessionTracker()
+
+    def test_ui_hints_structure(self):
+        self.tracker.record(detect_crisis("Hello"))
+        hints = self.tracker.get_ui_hints()
+        self.assertIn("session_escalating", hints)
+        self.assertIn("session_deescalating", hints)
+        self.assertIn("session_peak_level", hints)
+        self.assertIn("session_message_count", hints)
+
+    def test_ui_hints_escalation_warning(self):
+        """Escalating session should have warning hint."""
+        self.tracker.record(detect_crisis("Hello"))
+        self.tracker.record(detect_crisis("I want to die"))
+        hints = self.tracker.get_ui_hints()
+        if hints["session_escalating"]:
+            self.assertTrue(hints.get("escalation_warning"))
+            self.assertIn("suggested_action", hints)
+
+
+class TestCheckCrisisWithSession(unittest.TestCase):
+    """Test the convenience function combining detection + session tracking."""
+
+    def test_returns_combined_data(self):
+        tracker = CrisisSessionTracker()
+        result = check_crisis_with_session("I want to die", tracker)
+        self.assertIn("level", result)
+        self.assertIn("session", result)
+        self.assertIn("current_level", result["session"])
+        self.assertIn("peak_level", result["session"])
+        self.assertIn("modifier", result["session"])
+
+    def test_session_updates_across_calls(self):
+        tracker = CrisisSessionTracker()
+        check_crisis_with_session("Hello", tracker)
+        result = check_crisis_with_session("I want to die", tracker)
+        self.assertEqual(result["session"]["message_count"], 2)
+        self.assertEqual(result["session"]["peak_level"], "CRITICAL")
+
+
+class TestPrivacy(unittest.TestCase):
+    """Verify privacy-first design principles."""
+
+    def test_no_persistence_mechanism(self):
+        """Session tracker should have no database, file, or network calls."""
+        import inspect
+        source = inspect.getsource(CrisisSessionTracker)
+        # Should not import database, requests, or file I/O
+        forbidden = ["sqlite", "requests", "urllib", "open(", "httpx", "aiohttp"]
+        for word in forbidden:
+            self.assertNotIn(word, source.lower(),
+                f"Session tracker should not use {word} — privacy-first design")
+
+    def test_state_contained_in_memory(self):
+        """All state should be instance attributes, not module-level."""
+        tracker = CrisisSessionTracker()
+        tracker.record(detect_crisis("I want to die"))
+        # New tracker should have clean state (no global contamination)
+        fresh = CrisisSessionTracker()
+        self.assertEqual(fresh.state.current_level, "NONE")
+
+
+if __name__ == '__main__':
+    unittest.main()