fix: migrate hooks to stdin JSON input, fix duplicate main() calls, add threshold validation

- Migrate session-end.js and evaluate-session.js from CLAUDE_TRANSCRIPT_PATH
  env var to stdin JSON transcript_path (correct hook input mechanism)
- Remove duplicate main() calls that ran before stdin was read, causing
  session files to be created with empty data
- Add range validation (1-10000) on COMPACT_THRESHOLD in suggest-compact.js
  to prevent negative or absurdly large thresholds
- Add integration/hooks.test.js to tests/run-all.js so CI runs all 97 tests
- Update evaluate-session.sh to parse transcript_path from stdin JSON
- Update hooks.test.js to pass transcript_path via stdin instead of env var
- Sync .cursor/ copies

skills/continuous-learning/evaluate-session.sh

@@ -43,8 +43,13 @@ fi
 # Ensure learned skills directory exists
 mkdir -p "$LEARNED_SKILLS_PATH"
 
-# Get transcript path from environment (set by Claude Code)
-transcript_path="${CLAUDE_TRANSCRIPT_PATH:-}"
+# Get transcript path from stdin JSON (Claude Code hook input)
+# Falls back to env var for backwards compatibility
+stdin_data=$(cat)
+transcript_path=$(echo "$stdin_data" | grep -o '"transcript_path":"[^"]*"' | head -1 | cut -d'"' -f4)
+if [ -z "$transcript_path" ]; then
+  transcript_path="${CLAUDE_TRANSCRIPT_PATH:-}"
+fi
 
 if [ -z "$transcript_path" ] || [ ! -f "$transcript_path" ]; then
   exit 0