fix: improve worktree/session handling in cmd_start, cmd_continue, and cmd_init

cmd_continue:
- If worktree is missing but session exists, remove stale session and call cmd_start automatically
- This allows automatic recovery without user intervention

cmd_start:
- Check BOTH worktree AND session existence
- If only worktree exists (not session): remove worktree, recreate both
- If only session exists (not worktree): remove session, recreate both
- If both exist: tell user to use continue

cmd_init --force:
- Now destroys ALL sessions, worktrees, and logs for a clean slate
- Destroys base, pm-agent, all forked sessions, all worktrees, all logs

Daemon:
- Fixed wrong path in check_task_completion ($HOME/.kugetsu-worktrees -> $WORKTREES_DIR)

skills/kugetsu/scripts/kugetsu-session.sh

@@ -83,6 +83,10 @@ EOF
     if [ -n "$existing_base" ] && [ "$existing_base" != "null" ]; then
         if [ "$force" = true ]; then
             echo "Warning: Reinitializing sessions (force mode)" >&2
+            echo "Destroying all sessions, worktrees, and logs..." >&2
+            cmd_destroy --base -y 2>/dev/null || true
+            cmd_destroy --pm-agent -y 2>/dev/null || true
+            rm -f "$LOGS_DIR"/*.log 2>/dev/null || true
         else
             echo "Error: Base session already exists: $existing_base" >&2
             echo "Use --force to reinitialize" >&2
@@ -419,12 +423,12 @@ cmd_continue() {
     local issue_ref=$(python3 -c "import json; print(json.load(open('$session_path')).get('issue_ref', ''))" 2>/dev/null || echo "")
     
     if [ -z "$worktree_path" ] || [ ! -d "$worktree_path" ]; then
-        echo "Error: Worktree is missing for '$session_name'" >&2
-        echo "Removing stale session file..." >&2
+        echo "Warning: Worktree is missing for '$session_name'. Recovering..." >&2
         rm -f "$session_path"
         remove_issue_from_index "$session_name"
-        echo "Use 'kugetsu start $session_name' to create a new session." >&2
-        exit 1
+        echo "Calling cmd_start to create new session and worktree..." >&2
+        cmd_start "$session_name" "$message"
+        return $?
     fi
     
     if [ -z "$message" ]; then