fix(android): keep IME prompts usable

[omgoshjosh]

Summary

• reconcile Android edge-to-edge keyboard coordinates with the safe-area top inset
• bound question options in their own scroll surface while pinning navigation
• cap the multiline composer from live Android IME geometry and enable internal scrolling

Validation

• npm test (340 passing)
• npm run typecheck
• npm run check:versions

Evidence

• Reproduction: Android: chat input hidden behind keyboard #194 and /var/folders/fc/xccpf99d62b5_sc13zpgvjd80000gn/T/opencode/mobile-ime-repro-20260920/
• Real-device install/smoke is queued behind the broker active 10 GB iOS build lane; no capacity bypass was attempted.

Closes #194

[omgoshjosh]

QA physical Pixel candidate smoke: FAIL/BLOCKED for authoritative UI states, not a code failure.

Verified: commit 95b001d loaded from branch Metro on physical Pixel 8 Pro (38141FDJG00BG7), 1008x2244, portrait; bundle contains question-options-scroll, keyboardVerticalOffset, COMPOSER_MIN_HEIGHT, and scrollEnabled markers. npm test: 340/340; typecheck and version parity pass.

External blocker: installed compatible dev client persisted server URL 127.0.0.1:12400, so no session/question/composer screen could be reached. Attempting normal navigation opened an unrelated Google consent flow; no consent or app data change was made. No native rebuild or feature-code edit.

Artifacts: file:///var/folders/fc/xccpf99d62b5_sc13zpgvjd80000gn/T/opencode/mobile-ime-repro-20260920/candidate/branch-loaded.png, branch-loaded.xml, android.bundle.js, post-smoke.log, post-smoke.xml, metro-candidate.log. Device lease, adb reverse mappings, Metro process, and port claim were cleaned up.

[omgoshjosh]

QA PASS at 95b001d on Pixel 8 Pro 38141FDJG00BG7. The prior 127.0.0.1:12400 blocker was resolved by reproducing the question-aware mock endpoint and reversing 12400; Metro used host 13000 with device 8081 -> 13000 reverse. Evidence: /Users/josh/agents/media/mobile-ime-qa-95b001d-20260921/ and prior candidate bundle/log evidence at /private/var/folders/fc/xccpf99d62b5_sc13zpgvjd80000gn/T/opencode/mobile-ime-repro-20260920/candidate/.\n\nPASS: keyboard-visible question card independently scrolls lower choices while Dismiss/Next remain reachable; multiline composer shows multiple lines/caret and supports internal scroll/edit. Smoke coverage included keyboard dismissal, send, attachments, running/stop-capable mock path, compact resize, default and 1.5x text scale, safe-area geometry, portrait lock. Device class: 763x1536 app/window at 360dpi; physical screenshots 1008x2244. Cleanup verified: zero broker leases, no QA reverse mappings/processes/port claims, settings restored. No feature code or product files changed.

[omgoshjosh]

Final bug-focused review: PASS at 95b001d. No blocking regression found in bd18960 + 95b001d: Android now reconciles edge-to-edge IME/window coordinates, question choices have the bounded internal scroll owner with pinned navigation, and the multiline composer retains internal scrolling within its existing 120dp cap. iOS offset 90 is unchanged. Gates: 340 tests, typecheck, version parity; physical Pixel 8 Pro QA PASS: /Users/josh/agents/media/mobile-ime-qa-95b001d-20260921/. Residual risk: one physical Pixel/IME combination. Ready for maintainer review; not merged.