fix: proactively check memory status during thought tracking

Add periodic memory status auditing to the thinking engine. Every 50
thoughts (configurable via thinking_memory_check_every), the engine now
calls get_memory_status() and logs tier metrics (hot memory lines,
semantic vectors, vault files) both to the application log and to
data/memory_audit.log for persistent tracking.

Fixes #310

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/config.py

@@ -244,6 +244,7 @@ class Settings(BaseSettings):
     thinking_interval_seconds: int = 300  # 5 minutes between thoughts
     thinking_distill_every: int = 10  # distill facts from thoughts every Nth thought
     thinking_issue_every: int = 20  # file Gitea issues from thoughts every Nth thought
+    thinking_memory_check_every: int = 50  # check memory status every Nth thought
 
     # ── Gitea Integration ─────────────────────────────────────────────
     # Local Gitea instance for issue tracking and self-improvement.

src/timmy/thinking.py

@@ -305,6 +305,9 @@ class ThinkingEngine:
         # Post-hook: check workspace for new messages from Hermes
         await self._check_workspace()
 
+        # Post-hook: proactive memory status audit
+        self._maybe_check_memory_status()
+
         # Post-hook: update MEMORY.md with latest reflection
         self._update_memory(thought)
 
@@ -532,6 +535,47 @@ class ThinkingEngine:
         except Exception as exc:
             logger.warning("Thought distillation failed: %s", exc)
 
+    def _maybe_check_memory_status(self) -> None:
+        """Every N thoughts, run a proactive memory status audit and log results."""
+        try:
+            interval = settings.thinking_memory_check_every
+            if interval <= 0:
+                return
+
+            count = self.count_thoughts()
+            if count == 0 or count % interval != 0:
+                return
+
+            from timmy.tools_intro import get_memory_status
+
+            status = get_memory_status()
+
+            # Log summary at INFO level
+            tier1 = status.get("tier1_hot_memory", {})
+            tier3 = status.get("tier3_semantic", {})
+            hot_lines = tier1.get("line_count", "?")
+            vectors = tier3.get("vector_count", "?")
+            logger.info(
+                "Memory audit (thought #%d): hot_memory=%s lines, semantic=%s vectors",
+                count,
+                hot_lines,
+                vectors,
+            )
+
+            # Write to memory_audit.log for persistent tracking
+            audit_path = Path("data/memory_audit.log")
+            audit_path.parent.mkdir(parents=True, exist_ok=True)
+            timestamp = datetime.now(UTC).isoformat(timespec="seconds")
+            with audit_path.open("a") as f:
+                f.write(
+                    f"{timestamp}  thought={count}  "
+                    f"hot_lines={hot_lines}  "
+                    f"vectors={vectors}  "
+                    f"vault_files={status.get('tier2_vault', {}).get('file_count', '?')}\n"
+                )
+        except Exception as exc:
+            logger.warning("Memory status check failed: %s", exc)
+
     async def _maybe_file_issues(self) -> None:
         """Every N thoughts, classify recent thoughts and file Gitea issues.