v0.8.67: Add terminal shortcut QA for Hotbar Alt-number behavior

[Hmbown]

Problem

Hotbar dispatch is intentionally Alt-1 through Alt-8. The v0.8.66 local candidate now renders that chord in the sidebar and docs, but v0.8.67 still needs real terminal QA so the advertised control matches what users can actually press.

Evidence

• The dispatch path recognizes plain terminal Alt-number only and rejects bare digits, Ctrl-number, Super/Cmd-number, 0, and 9.
• F1 is already help, and Cmd-number is commonly reserved by terminal apps for tab/window switching.
• Modal ownership must remain clear: command palette, slash menu, setup wizard, approval views, decision cards, onboarding, and other modal surfaces should block Hotbar numeric ownership.

Expected behavior

The Hotbar should feel like a game-style command bar without implying unsupported shortcuts. The visible UI, docs, setup copy, and QA matrix should all say the same thing.

Suggested QA matrix

• macOS Terminal.app, iTerm2, Ghostty, and Kitty: verify Alt/Option-1 through Alt/Option-8 dispatch when the terminal forwards Meta/Alt.
• Verify bare 1 through 8 insert text in the composer and do not trigger Hotbar.
• Verify Cmd-1 through Cmd-8 and F-keys are not presented as Hotbar shortcuts unless intentionally implemented later.
• Verify F1 remains help.
• Verify AltGr and non-US keyboard layouts do not break normal text entry.
• Verify modal/setup/onboarding/slash-menu/approval/decision-card ownership blocks Hotbar digits.

Acceptance criteria

• A linked terminal checklist records terminal names, OS, key settings, and pass/fail notes.
• docs/evidence/hotbar-qa-matrix.md or a linked v0.8.67 QA artifact includes the manual results.
• Any terminal-specific caveats are reflected in /hotbar help, docs, and setup copy.
• Unit tests continue to prove the model/UI dispatch contract: Alt-1..8 only, no bare digits, no Cmd/F-key implication.

Related: #3731, #3408, #3411, #2072, #3395, #3243.