fix(kugetsu): prevent excess agent spawning with flock + sequential processing

- count_active_dev_sessions() now excludes pm-agent.json from count
- process_queue() now calls kugetsu start directly (not opencode run)
- process_queue() uses dynamic batch size = available_slots
- process_queue() has retry logic (max 3 attempts) on failure
- cmd_start() now uses flock around critical section
- Added notification types: task_queued, task_dequeued, task_started, task_completed, task_error
- Removed QUEUE_DAEMON_BATCH_SIZE config (no longer needed)

Fixes issue #146

.github/ISSUES/fix-queue-daemon-excess-agents.md

@@ -63,5 +63,5 @@ New notification types:
 
 - [x] Issue created
 - [x] Implementation
-- [x] PR created (#147)
+- [ ] PR created
 - [ ] Merged

skills/kugetsu/scripts/kugetsu

@@ -1145,11 +1145,6 @@ parse_issue_ref_from_message() {
         owner=$(echo "$full_path" | cut -d'/' -f2)
         repo=$(echo "$full_path" | cut -d'/' -f3)
         issue_number=$(echo "$full_path" | grep -oE '[0-9]+$' | head -1)
-    elif echo "$message" | grep -qE '[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+#[0-9]+'; then
-        gitserver=$(echo "$message" | grep -oE '[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+' | head -1)
-        owner=$(echo "$gitserver" | cut -d'/' -f2)
-        repo=$(echo "$gitserver" | cut -d'/' -f3)
-        issue_number=$(echo "$message" | grep -oE '#[0-9]+' | grep -oE '[0-9]+' | head -1)
     elif echo "$message" | grep -qE '[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+#([0-9]+)'; then
         owner=$(echo "$message" | grep -oE '[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+#' | sed 's/#$//' | cut -d'/' -f1)
         repo=$(echo "$message" | grep -oE '[a-zA-Z0-9_.-]+/[a-zA-Z0-9_.-]+#' | sed 's/#$//' | cut -d'/' -f2)