fix(tui): let Tab focus Playbook selection menu

[edwin-zvs]

Summary

• make bare Tab focus the visible Playbook selection context menu, then cycle its rows
• make the first Escape dismiss the menu while preserving selected text, so Tab can indent it; a second Escape clears the selection
• preserve backward menu navigation and selected-text outdent behavior, including Shift+Tab terminal variants
• retain C-o as a compatibility alias that can reopen a dismissed menu
• update spec 0196 and focused state, indent, compatibility, and render tests

Verification

• focused Tab focus / Escape / indentation transition test: 1 passed
• focused two-Escape state transition test: 1 passed
• selection-menu render suite: 5 passed
• run-row focus render test: 1 passed
• inline-code contrast tests from PR fix(playbook): improve inline code contrast #1284: 2 passed
• cargo build

Before the final merge-train update, broader validation also passed:

• all 337 Playbook-filtered CLI tests
• full CLI suite: 1,429 passed plus reconnect (one confirmed origin/main truecolor baseline test skipped)
• TUI smoke e2e: 3 passed

Repository-wide cargo fmt --check proposes extensive unrelated churn on untouched main; no formatter churn was applied. git diff --check is clean.

Reviewer media

Not attached: deterministic VHS capture was stopped to prioritize the merge-train handoff.