Add mobile Steer and Queue follow-up modes

[GeeeekExplorer]

Adds a persisted Queue / Steer choice to the compact mobile composer for capable Claude and Codex sessions. Queue is the default; unknown future values fall back to Queue without discarding other settings.

Delivery

• One optional encrypted message field and a session capability flag.
• Queue keeps waiting input local until completion, preserving /clear; Steer stays within compatible settings and command boundaries.
• Claude uses an async input generator and SDK next priority. Existing thinking state gates done notifications; unacknowledged delivery ends the query with a warning.
• Codex uses turn/steer. Definite rejection restores input; uncertain delivery is reported without replay.
• Both adapters use the queue's restore callback, preserving original items, order and attachments. Normal Claude permission hot updates remain available.

Validation

• 100 focused CLI tests and 56 app tests passed; CLI build and app typecheck passed.
• Real Claude 2.1.280 against a local mock API: Steer folded into the running turn, Queue ran afterward, EOF drained input. Session persistence was disabled; no Happy sessions or transcripts were created.
• Physical mobile controls have not been tested on a device.

Diff: production code +271/-58, tests +178/-12, translations +30/-1; total +479/-71. Local model defaults, model catalogs and network proxy patches are separate from this PR.

Refs #1867.