fix(kugetsu): call fix_session_permissions before forking

- Call fix_session_permissions in cmd_start before forking to ensure
  base session has correct permissions for external_directory access
- Add debug logging to show forked session's directory and permissions
  after creation to help diagnose permission inheritance issues

skills/kugetsu/scripts/kugetsu

@@ -1246,6 +1246,8 @@ cmd_start() {
     local fork_log="$SESSIONS_DIR/$session_file.fork.log"
     local opencode_db="${OPENCODE_DB:-$HOME/.local/share/opencode/opencode.db}"
     
+    fix_session_permissions
+    
     if [ "$DEBUG_MODE" = true ]; then
         (cd "$worktree_path" && opencode run "$message" --fork --session "$base_session_id" 2>&1) | tee "$fork_log" &
     else
@@ -1317,6 +1319,20 @@ for row in cursor.fetchall():
         exit 1
     fi
 
+    if [ "$DEBUG_MODE" = true ]; then
+        echo "[DEBUG] Forked session permissions check:"
+        python3 -c "
+import sqlite3
+conn = sqlite3.connect('$opencode_db')
+cursor = conn.cursor()
+cursor.execute(\"SELECT id, directory, permission FROM session WHERE id = '$new_session_id'\")
+for row in cursor.fetchall():
+    print('  ID:', row[0])
+    print('  Directory:', row[1])
+    print('  Permission:', row[2])
+" 2>/dev/null || echo "  (failed to query DB)"
+    fi
+
     printf '{"type": "forked", "issue_ref": "%s", "opencode_session_id": "%s", "worktree_path": "%s", "created_at": "%s", "state": "idle"}\n' \
         "$issue_ref" "$new_session_id" "$worktree_path" "$(date -Iseconds)" > "$SESSIONS_DIR/$session_file"