fix(mobile): integrate a compact queue above the composer

[bobleer]

A queued message on mobile web rendered in normal page flow while the composer floated over it, hiding the message and its actions. The queue now lives above the editor inside the same measured composer container, so keyboard positioning and transcript bottom clearance account for both.

The queue uses a compact themed card with a message count, collapse/expand control, scrollable bounded contents, and an optional delivery-behavior explanation. Send-now and removal use small inline icons with 40px touch targets instead of full-width action rows; a single queued message occupies 91px. Both actions remain available without covering the editor. English, Simplified Chinese, and Traditional Chinese labels are updated.

Validation:

• 16 host queue tests passed, including browser layout checks at 320×568, 390×844, 390×420, 768×800, and 1200×900; collapse, help, promote, and last-item removal are covered.
• Mobile component contracts, TypeScript, production build, i18n, typography, repository hygiene, and all 23 theme/color surfaces passed.
• Visually inspected the real queue/composer components in the Codex in-app browser at phone width, reduced viewport height, and narrow light mode. Host RPCs are simulated. The reduced viewport is a keyboard-height simulation, not a physical-phone keyboard test.

The earlier disconnected-client outbox and idempotency behavior is unchanged. No live deployment is included.