Add orphaned job prevention in generate_book_task

- Guard checks at task start verify: run exists in DB, project folder exists,
  bible.json exists and is parseable, and bible has at least one book
- Any failed check marks the run as 'failed' and returns early, preventing
  jobs from writing to the wrong book or orphaned project directories

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/tasks.py

@@ -107,6 +107,56 @@ def generate_book_task(run_id, project_path, bible_path, allow_copy=True, feedba
 
     _task_log(f"Task picked up by Huey worker. project_path={project_path}")
 
+    # 0. Orphaned Job Guard — verify that all required resources exist before
+    #    doing any work. If a run, project folder, or bible is missing, terminate
+    #    silently and mark the run as failed to prevent data being written to the
+    #    wrong book or project.
+    db_path_early = os.path.join(config.DATA_DIR, "bookapp.db")
+
+    try:
+        with sqlite3.connect(db_path_early, timeout=10) as _conn:
+            _row = _conn.execute("SELECT id FROM run WHERE id = ?", (run_id,)).fetchone()
+        if not _row:
+            _task_log(f"ABORT: Run #{run_id} no longer exists in DB. Terminating silently.")
+            return
+    except Exception as _e:
+        _task_log(f"WARNING: Could not verify run #{run_id} existence: {_e}")
+
+    if not os.path.isdir(project_path):
+        _task_log(f"ABORT: Project folder missing ({project_path}). Marking run #{run_id} as failed.")
+        try:
+            _robust_update_run_status(db_path_early, run_id, 'failed',
+                                      end_time=datetime.utcnow().isoformat())
+        except Exception: pass
+        return
+
+    if not os.path.isfile(bible_path):
+        _task_log(f"ABORT: Bible file missing ({bible_path}). Marking run #{run_id} as failed.")
+        try:
+            _robust_update_run_status(db_path_early, run_id, 'failed',
+                                      end_time=datetime.utcnow().isoformat())
+        except Exception: pass
+        return
+
+    # Validate that the bible has at least one book entry
+    try:
+        with open(bible_path, 'r', encoding='utf-8') as _bf:
+            _bible_check = json.load(_bf)
+        if not _bible_check.get('books'):
+            _task_log(f"ABORT: Bible has no books defined. Marking run #{run_id} as failed.")
+            try:
+                _robust_update_run_status(db_path_early, run_id, 'failed',
+                                          end_time=datetime.utcnow().isoformat())
+            except Exception: pass
+            return
+    except Exception as _e:
+        _task_log(f"ABORT: Could not parse bible ({bible_path}): {_e}. Marking run #{run_id} as failed.")
+        try:
+            _robust_update_run_status(db_path_early, run_id, 'failed',
+                                      end_time=datetime.utcnow().isoformat())
+        except Exception: pass
+        return
+
     # 1. Setup Logging
     log_filename = f"system_log_{run_id}.txt"