v0.8.68: Localize Hotbar setup wizard chrome and add non-English coverage

[Hmbown]

Problem

The Hotbar setup wizard is becoming an optional v0.8.68 setup surface, but its wizard chrome and state text are still mostly hard-coded English. That makes the setup lane feel unfinished in non-English locales even when command descriptions themselves are localized.

This localization work should reflect the current product direction: Hotbar is hidden by default in v0.8.66 (#3807) and introduced later as opt-in personalization.

Evidence

• Hotbar command/keybinding strings exist in most locale surfaces, but zh-Hant coverage appears to lag the Hotbar keys present elsewhere.
• The wizard view owns user-facing title/help/status/action text in crates/tui/src/tui/hotbar/setup.rs, including source labels, empty states, disabled/default-off state, save/cancel hints, validation/status lines, and slot/action descriptions.
• v0.8.67 Setup: docs, screenshots, localization, and constitution copy refresh #3412 tracks broad setup docs/localization; this issue is the focused Hotbar setup child so acceptance can be tested independently.

Expected behavior

Opening /hotbar or the setup wizard Hotbar step should not drop users into a mostly-English setup surface when the rest of the TUI is localized. It should also localize the distinction between default-off, explicitly disabled, configured, partial, and unknown-action states.

Likely implementation areas

• crates/tui/src/tui/hotbar/setup.rs
• crates/tui/src/localization.rs
• shipped locale JSON/string tables
• Hotbar setup tests/snapshots

Acceptance criteria

• Hotbar setup title, source/help/status labels, default-off/empty/disabled/prefill/ready text, save/cancel hints, and validation errors route through localization IDs or an intentional fallback layer.
• Shipped locales either cover the Hotbar setup strings or explicitly document fallback behavior.
• At least one non-English test/snapshot proves the Hotbar setup wizard does not render mostly in English.
• zh-Hant has Hotbar command/keybinding coverage parity or a documented fallback.
• Setup text presents Hotbar as optional opt-in behavior, not required first-run chrome.

Related: #3807, #3412, #3408, #2071, #2072, #790.