Bug: side panel can render blank/non-usable in Chromium

[arnaudassoumani-collab]

Problem

In Chromium, the OpenBrowser side panel can open but render as effectively blank/non-usable (no accessible controls or visible content).

Repro

1. Load unpacked extension.
2. Pin OpenBrowser in toolbar.
3. Click the OpenBrowser icon to open side panel.
4. Observe panel with no usable/visible interface.

Expected

Panel should remain usable with visible controls and a recovery path if runtime errors occur.

Notes

• A proposed fix is available in PR fix(extension): recover blank side panel + contrast hardening (v1.0.7) #11.
• Root cause appears to be an unhandled runtime render failure + insufficient theme fallback contrast in some environments.

Acceptance criteria

• No full blank panel in normal usage.
• If render fails, user sees a recovery UI (reload/reset).
• Text/icons remain readable on both dark and light themes.

[arnaudassoumani-collab]

Tracked in PR #11: #11