fix: resolve concrete issue-board regressions

[arzafran]

Summary

Clear ten concrete correctness, automation, performance, and CI issues from the repository board.

The first commit contains regression coverage only, so CI records the pre-fix failures. The second commit contains the production fixes and removes the obsolete CI quarantine.

• tolerate duplicate panel IDs while restoring sessions
• record clean shutdown only after termination is certain
• dispatch the configurable Open Review shortcut
• return stable browser workspace and surface references
• remove dead browser dialog state and macOS 11 branches
• reduce watched terminal output to one bounded snapshot per surface
• make missing or invalid GhosttyKit artifacts fail deterministically
• re-enable the last-surface Cmd+W regression on CI

Validation

• Tagged Debug build: ./scripts/reload.sh --tag clear-board
• git diff --check
• Red CI recorded on the test-only commit: duplicate-session restore and GhosttyKit fallback checks failed as intended
• Green CI required before merge

Closes #222
Closes #229
Closes #230
Closes #273
Closes #279
Closes #280
Closes #282
Closes #283
Closes #289
Closes #290