fix: improve worktree/session handling in cmd_start and cmd_continue

cmd_continue:
- Check if worktree exists before continuing
- If worktree is missing, remove stale session and exit with error
- Tell user to use cmd_start instead

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

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

skills/kugetsu/scripts/kugetsu-queue-daemon.sh

@@ -44,7 +44,7 @@ check_task_completion() {
 
     if [ -n "$pid" ] && [ "$pid" != "None" ]; then
         if ! kill -0 "$pid" 2>/dev/null; then
-            local worktree_path=$(issue_ref_to_worktree_path "$issue_ref" "$HOME/.kugetsu-worktrees")
+            local worktree_path=$(issue_ref_to_worktree_path "$issue_ref" "$WORKTREES_DIR")
             local has_commits=false
 
             if [ -d "$worktree_path" ] && [ -d "$worktree_path/.git" ]; then
@@ -64,7 +64,7 @@ check_task_completion() {
         fi
     else
         if [ -n "$session_id" ] && ! opencode session list 2>/dev/null | grep -q "$session_id"; then
-            local worktree_path=$(issue_ref_to_worktree_path "$issue_ref" "$HOME/.kugetsu-worktrees")
+            local worktree_path=$(issue_ref_to_worktree_path "$issue_ref" "$WORKTREES_DIR")
             local has_commits=false
 
             if [ -d "$worktree_path" ] && [ -d "$worktree_path/.git" ]; then

skills/kugetsu/scripts/kugetsu-session.sh

@@ -309,26 +309,44 @@ cmd_start() {
         exit 1
     fi
     
+    local session_file=$(issue_ref_to_filename "$issue_ref")
+    local session_path="$SESSIONS_DIR/$session_file"
+    local worktree_exists=false
+    
     if worktree_exists "$issue_ref"; then
-        echo "Issue '$issue_ref' already has a worktree. Use 'kugetsu continue' instead."
+        worktree_exists=true
+    fi
+    
+    local session_exists=false
+    if [ -f "$session_path" ]; then
+        session_exists=true
+    fi
+    
+    if $worktree_exists && $session_exists; then
+        echo "Issue '$issue_ref' already has a worktree and session." >&2
+        echo "Use 'kugetsu continue $issue_ref' to continue work." >&2
         exit 1
     fi
     
+    if $worktree_exists && ! $session_exists; then
+        echo "Warning: Worktree exists but session is missing. Removing worktree to recreate both..." >&2
+        remove_worktree_for_issue "$issue_ref"
+        worktree_exists=false
+    fi
+    
+    if ! $worktree_exists && $session_exists; then
+        echo "Warning: Session exists but worktree is missing. Removing stale session to recreate both..." >&2
+        rm -f "$session_path"
+        remove_issue_from_index "$issue_ref"
+        session_exists=false
+    fi
+    
     local active_count=$(count_active_dev_sessions)
     if [ "$active_count" -ge "${MAX_CONCURRENT_AGENTS:-3}" ]; then
         echo "Error: Max concurrent agents (${MAX_CONCURRENT_AGENTS:-3}) reached. Use 'kugetsu continue' or wait for an agent to finish." >&2
         exit 1
     fi
     
-    local session_file=$(issue_ref_to_filename "$issue_ref")
-    local session_path="$SESSIONS_DIR/$session_file"
-    
-    if [ -f "$session_path" ]; then
-        echo "Session file already exists: $session_file"
-        echo "Use 'kugetsu continue $issue_ref' to continue work."
-        exit 1
-    fi
-    
     create_worktree "$issue_ref" "$WORKTREES_DIR"
     
     local new_session_id=$(create_session "$base_session_id")
@@ -400,16 +418,21 @@ cmd_continue() {
     local worktree_path=$(python3 -c "import json; print(json.load(open('$session_path')).get('worktree_path', ''))" 2>/dev/null || echo "")
     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 '$session_name'" >&2
+        echo "Removing stale session file..." >&2
+        rm -f "$session_path"
+        remove_issue_from_index "$session_name"
+        echo "Use 'kugetsu start $session_name' to create a new session." >&2
+        exit 1
+    fi
+    
     if [ -z "$message" ]; then
         message=$(build_dev_agent_message "$issue_ref" "")
     fi
     
-    if [ -n "$worktree_path" ] && [ -d "$worktree_path" ]; then
     cd "$worktree_path"
     nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '$message' --session '$opencode_session_id'" >> "$LOGS_DIR/dev-$opencode_session_id.log" 2>&1 &
-    else
-        nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '$message' --session '$opencode_session_id'" >> "$LOGS_DIR/dev-$opencode_session_id.log" 2>&1 &
-    fi
 }
 
 cmd_list() {