fix: Python 3.6 compat + allow CURRENT_STATE.md override

- Replace 'Path | None' union syntax with 'Optional[Path]' (typing import)
  so continuity_doctor.py works on Python 3.6+
- Remove message-count guard in agent_end hook that blocked state writes
  when realUserMsgs.length < 2; agents can now update CURRENT_STATE.md
  regardless of conversation length

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

index.js

@@ -258,14 +258,7 @@ const plugin = {
         return cleaned.length > 10;
       });
 
-      // Don't overwrite meaningful state with trivial conversations
-      // (e.g., "/new" then "what was my secret?" — only 1 real message)
       const existing = readFile(statePath);
-      if (existing && buildSnapshot(existing) && realUserMsgs.length < 2) {
-        log.info?.("[memory-continuity] Conversation too short to overwrite existing state (" + realUserMsgs.length + " real msgs)");
-        return;
-      }
-
       const newState = extractStateFromMessages(messages);
       if (!newState) {
         log.info?.("[memory-continuity] No extractable state from conversation");

scripts/continuity_doctor.py

@@ -15,6 +15,7 @@ import sys
 import re
 from datetime import datetime, timezone
 from pathlib import Path
+from typing import Optional
 
 
 # ---------------------------------------------------------------------------
@@ -78,7 +79,7 @@ PLACEHOLDER_PATTERNS = [
 # Checks
 # ---------------------------------------------------------------------------
 
-def check_existence(workspace: Path, report: DiagnosticReport) -> Path | None:
+def check_existence(workspace: Path, report: DiagnosticReport) -> Optional[Path]:
     """Check that memory/CURRENT_STATE.md exists."""
     state_file = workspace / "memory" / "CURRENT_STATE.md"
     if not state_file.exists():