fix(doctor): surface cached extension version when disconnected to detect version mismatch

[hyyu189]

Problem

When the Chrome Web Store auto-upgrades the extension but the npm CLI stays pinned at an older version, the bridge silently breaks. opencli doctor shows only "extension not connected" with no indication of a version mismatch — the user (and automated agents) have no way to diagnose the root cause.

Repro

1. Chrome Web Store auto-updates extension to v1.0.19
2. npm CLI stays at v1.8.0
3. opencli doctor → Extension: not connected (silent)
4. All COOKIE / INTERCEPT / UI adapters fail with extension not connected

The existing compat-range check (lines 168-185 in doctor.ts) correctly detects protocol mismatches when the extension IS connected, but it never runs when the extension is disconnected.

Fix

Two minimal changes:

1. update-check.ts: Export getCachedExtensionVersion() to read currentExtensionVersion from the daemon's shared cache. The daemon already writes this on every successful WebSocket handshake via recordExtensionVersion() — we just weren't reading it in the doctor path.

2. doctor.ts: When the extension is disconnected (daemonRunning && !extensionConnected), check the cached extension version. If found, append a version-mismatch hint to the issues list, suggesting npm install -g + restart Chrome.

Example output (before → after)

Before:

[OK] Daemon: running on port 19825
[MISSING] Extension: not connected
Issues:
  • Daemon is running but the Chrome/Chromium extension is not connected.

After:

[OK] Daemon: running on port 19825
[MISSING] Extension: not connected
Issues:
  • Daemon is running but the Chrome/Chromium extension is not connected.
  • Extension was previously connected at v1.0.19 but is now unreachable.
    CLI is v1.8.0. This may indicate a version mismatch from Chrome Web Store auto-upgrade.
    Try: npm install -g @jackwener/opencli && opencli daemon restart
    Then restart Chrome to reload the extension service worker.

Testing

All existing tests pass:

• src/doctor.test.ts — 17/17
• Full npm test --project unit — 1175 passed, 1 skipped