feat: enable SQLite WAL mode for all databases (AGI ticket #1) (#153)

src/timmy/memory_system.py

@@ -10,7 +10,6 @@ Handoff Protocol:
 - Inject into next session automatically
 """
 
-import hashlib
 import logging
 import re
 from datetime import datetime, timezone
@@ -85,9 +84,9 @@ class HotMemory:
 
 ## Current Status
 
-**Agent State:** Operational  
-**Mode:** Development  
-**Active Tasks:** 0  
+**Agent State:** Operational
+**Mode:** Development
+**Active Tasks:** 0
 **Pending Decisions:** None
 
 ---
@@ -112,7 +111,7 @@ class HotMemory:
 
 ## User Profile
 
-**Name:** (not set)  
+**Name:** (not set)
 **Interests:** (to be learned)
 
 ---
@@ -160,9 +159,9 @@ class VaultMemory:
         filepath = self.path / namespace / filename
 
         # Add header
-        full_content = f"""# {name.replace('_', ' ').title()}
+        full_content = f"""# {name.replace("_", " ").title()}
 
-> Created: {datetime.now(timezone.utc).isoformat()}  
+> Created: {datetime.now(timezone.utc).isoformat()}
 > Namespace: {namespace}
 
 ---
@@ -236,8 +235,8 @@ class VaultMemory:
 
 ## Basic Information
 
-**Name:** (unknown)  
-**Location:** (unknown)  
+**Name:** (unknown)
+**Location:** (unknown)
 **Occupation:** (unknown)
 
 ## Interests & Expertise
@@ -256,9 +255,7 @@ class VaultMemory:
 ---
 
 *Last updated: {date}*
-""".format(
-            date=datetime.now(timezone.utc).strftime("%Y-%m-%d")
-        )
+""".format(date=datetime.now(timezone.utc).strftime("%Y-%m-%d"))
 
         profile_path.write_text(default)
 
@@ -280,7 +277,7 @@ class HandoffProtocol:
         """Write handoff at session end."""
         content = f"""# Last Session Handoff
 
-**Session End:** {datetime.now(timezone.utc).isoformat()}  
+**Session End:** {datetime.now(timezone.utc).isoformat()}
 **Duration:** (calculated on read)
 
 ## Summary
@@ -462,5 +459,26 @@ class MemorySystem:
         return "\n\n---\n\n".join(context_parts)
 
 
-# Module-level singleton
-memory_system = MemorySystem()
+# ── Lazy singleton ────────────────────────────────────────────────────────────
+_memory_system: MemorySystem | None = None
+
+
+def get_memory_system() -> MemorySystem:
+    """Return the module-level MemorySystem, creating it on first access."""
+    global _memory_system
+    if _memory_system is None:
+        _memory_system = MemorySystem()
+    return _memory_system
+
+
+def reset_memory_system() -> None:
+    """Reset the singleton for test isolation."""
+    global _memory_system
+    _memory_system = None
+
+
+def __getattr__(name: str):
+    """Module-level __getattr__ for lazy backward-compatible access."""
+    if name == "memory_system":
+        return get_memory_system()
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")