fix(mobile): terminal and layout fixes for touch devices

[aakhter]

Summary

Mobile-focused fixes for the web terminal UI on touch devices, extracted as a focused change set:

• Keyboard accessory: prevent vertical scroll on the accessory bar; keep mobile keyboard controls below the terminal; remove the redundant /compact button.
• Layout/overlap: prevent mobile toolbar overlap; isolate mobile resize and toolbar layout.
• Input visibility: use native terminal input by default on mobile; keep the phone input visible above the keyboard; force a visible composer on touch devices; anchor input at the cursor; iPhone focus polish; keep the xterm input focusable.
• CJK: show CJK input above the keyboard via a local-echo overlay.
• Touch: preserve terminal touch scrolling.
• Tabs: larger tab-menu tap target; preserve mobile keyboard state on tab switch.
• Misc: contain the mobile mic-recording glow.
• Tests: mobile layout/keyboard/tabs coverage and visual-regression snapshots.

Verification

• tsc --noEmit passes
• eslint passes
• Prettier format check passes

(Mobile visual-regression snapshots are included; CI/maintainer can re-baseline if device rendering differs.)

[Ark0N]

Thanks @aakhter — the mobile fixes are well-aimed and the 24 new behavioral tests are genuinely high quality (they assert real DOM geometry, computed CSS, focus state, and the resize state machine rather than just snapshots; all pass locally). A few things block landing:

Blockers

1. Hard dependency on #112.selectSession here calls scrollToLastNonEmptyLine() and _clearTerminalLoadState(), reads _xtermSnapshots, and the tab template references a per-session loadState — none of these exist on master; they're all introduced by #112. On bare master this is a TypeError/ReferenceError on every tab switch. So this must land after#112. It also looks branched off an early version of #112 (it independently re-adds an identical _resetTerminalForReplay() and carries the pre-#112selectSession body), so a wholesale merge would silently revert #112's terminal rewrite. Please rebase onto the final reworked #112.

2. Resize-arbitration guard freezes mobile width. The cols < _ptyCols guard in session.ts resize() means a mobile-only session's PTY never narrows below the 120-col default → narrow phones render clipped. → allow the shrink for genuinely smaller viewports (and ideally cover rows-only shrink + re-grow in the unit test).

3. Solo/detached header broken.index.html removes soloSessionTitle and soloRedockBtn, but app.js_applySoloMode (around 1025) still references them.

Should-fix

• The new mobile-header utility toggle button has no desktop hide rule → it shows at ≥1024px.
• The 18 binary visual-regression PNGs are environment-specific; freezing contributor-machine baselines into the repo will be flaky across machines/CI. → generate them in a canonical CI job, or gate the visual suite as allow-fail.
• AGENTS.md largely duplicates CLAUDE.md — consider pointing to it instead to avoid drift.

Once #112 is reworked and this is rebased on top with the resize guard fixed, the test coverage here is a real asset. Thanks again.

[Ark0N]

Re-reviewed after rebasing this onto current master (post-#112-final and post-#113) and pushing fixes directly to the branch (maintainer edits). All three blockers and the should-fixes are addressed; summary of what changed:

Blockers

1. #112 entanglement — rebased onto master c29475e. The early-#112 artifacts are gone (_xtermSnapshots, codeman-xs-* localStorage, the pre-rework selectSession body, the duplicate _resetTerminalForReplay, a dead getAttachmentHistoryForPersist test stub). An 11-agent diff audit verified the final #112 pane-buffer machinery and the #113 envelope migration survive byte-identical — the mobile changes are now purely additive.
2. Resize arbitration redesigned — the cols < _ptyCols guard (which froze a mobile-only session at the 120-col spawn default) is replaced with connection-scoped desktop sizing claims: ws-routes registers a claim per socket on a desktop-typed resize and releases it on close (or when that connection later reports a small viewport); Session.resize() ignores mobile/tablet resizes only while a desktop claim is live. A phone alone fully controls its size (shrink, rows-only, re-grow — all unit-tested); a phone glancing at a desktop-driven session can't reflow it. Wiring fixes that came out of the audit: ws.onopen now sends a typed resize (otherwise claims were never registered in the canonical flow), and throttledResize sends typed WS-first resizes (so phone rotation arbitrates and a desktop narrowing past 768px releases its stale claim). mobile-handlers' keyboard resize declares its viewport type too.
3. Solo header restored — #soloSessionTitle + #soloRedockBtn are back in index.html alongside the new utility toggle; _applySoloMode resolves all elements (chromium-verified).

Should-fixes

• The utility toggle now has a base display:none (it leaked onto desktop ≥769px); mobile/tablet media queries re-enable it. Verified hidden at 1440px, visible+functional at 390px.
• The 18 visual-regression PNGs are reverted to master's baselines — 8 of the behavioral tests already fail purely from environment rendering differences on a second machine, so contributor-machine baselines would be flaky as predicted. The 24 behavioral tests are kept (84/92 pass here; the 8 failures reproduce identically on the unmodified branch, i.e. environment-sensitivity, not regressions).
• AGENTS.md is now a pointer to CLAUDE.md.

Additional fixes found by the post-rebase audit

• Desktop tab clicks stopped focusing the terminal (the preserveKeyboard ternary mapped desktop to never-focus, defeating master's gesture-stack focus). Focus policy now lives in _shouldFocusTerminalForTabSwitch(): desktop always focuses, touch only while the keyboard is open — your intended mobile behavior, minus the desktop regression. E2E-verified with a real session.
• cjkInputEnabled was silently ignored on touch phones/tablets while its App Settings checkbox stayed toggleable. The explicit user setting is honored everywhere again; mobile keeps native-input-by-default via the cjkInputEnabled: false mobile default.
• _handleCjkInput swallowed multi-byte ESC sequences (hardware-keyboard arrows on the composer) into local-echo pending text — now forwarded to the PTY like the onData path; its backspace path also syncs the per-session flushed maps.

Known accepted tradeoffs (documented in the session.ts claims docblock): claims are WS-only (the stateless HTTP fallback can't claim), viewport typing is width-based (a landscape iPad classifies as desktop), and closeMobileHeaderUtilities is currently unused — the tray only closes via the toggle. Fine to iterate on later.

The keyboard/layout/tabs behavioral tests are genuinely good coverage — thanks for those. Merging once CI is green.