Release v0.3.4: recover from hung window capture

[sbrants]

Summary

• Timebox window capture on a helper thread (5s) so a hung emulator capture no longer wedges the scanner while the UI still says scanning.
• Log capture outage reason/recovery, stall stage via watchdog, panics, and app version on every log line; show a not-capturing banner with distinct minimized/stalled statuses.
• Fix debug-package screenshots grabbing File Explorer when the title mentions WaveTrace; probe OS window state (visible/minimized/cloaked) into target-window.json.

Test plan

• New run on MuMu / Windows: confirm continuous polling past the first few seconds
• Minimize (or move to another virtual desktop) the game window: banner appears and log shows capture unavailable with os_windows=[...]
• Restore the window: capture restored after … appears and scanning resumes
• Generate a debug package: Dashboard/History/Settings screenshots are the WaveTrace UI (not Explorer)
• Confirm log lines are stamped v0.3.4
• CI green; tag v0.3.4 on main after merge