fix: clear IndexedDB/localStorage before each query to prevent stale-cache bug

[koffuxu]

Problem

NotebookLM persists the full conversation history in the browser's IndexedDB. Because ask_question.py uses a persistent Chrome profile (user_data_dir), every run reloaded the entire accumulated history from previous sessions. This caused two failure modes:

1. Wrong answer returned – the answer-detection loop found an old message that appeared "stable" and returned it instead of waiting for the actual response.
2. Timeout – after multiple runs, queued/pending answers from prior sessions filled the conversation. The loop waited for a new message that never arrived within the 2-minute window.

Fix

scripts/ask_question.py

• Navigate to the root origin first (https://notebooklm.google.com/) and wipe localStorage, sessionStorage, and all IndexedDB databases via page.evaluate() before loading the target notebook. This ensures the page always starts with 0 messages.
• Simplify response detection: set previous_count = 0 (no pre-snapshot needed) and accept any response where count > 0 or text changed, stable across 3 consecutive polls (~1.5 s).
• JS focus() before typing to bypass any lingering Material Design overlay backdrops that can block click() after UI interactions.
• Wait for textarea to clear after pressing Enter as a reliable confirmation that the question was accepted.

scripts/browser_utils.py

• Use click(force=True) in StealthUtils.human_type() to bypass overlay backdrops.

Testing

Verified with headless Chromium on macOS. Query "方言识别支持哪几种方言？" returns a correct, on-topic answer in under 5 seconds (3 stable polls).

🤖 Generated with Claude Code