feat(web): move the composer's + and mic buttons into the control row

[NoahHendrickson]

The + (attach) and mic buttons sat beside the prompt, and an idle mic took over the send slot whenever the prompt was empty. They now sit at the left end of the composer's control row, in the order [+] [mic] [Full access] [Build/Plan], with model and effort still on the right. Send is the only button beside the prompt.

Behaviour

• An empty prompt shows send (disabled) in its slot. The mic no longer takes that slot while idle, and it no longer competes with the resume action.
• A live dictation session still takes the send slot: X, waveform and check, as before. The mic in the control row stays where it is but is disabled, so the row doesn't shift. + is disabled during a session, as before.
• The draft (new-agent) box and the dictation layouts no longer reserve space for + in the prompt row; the prompt just stacks above the send row.

Visible side effects

• + and the mic are now 20px squares with 12px icons in the row's grey, to match Full access and Build/Plan. Before, they were 24px and white in dark mode.
• They hide whenever the control row does: during a pending approval, when the mobile composer is collapsed, and while the mobile answer buttons are showing.
• On narrow windows, Full access and Build/Plan collapse into the ⋯ menu slightly sooner.

Changes: ChatComposer.tsx (the dictation slot gate, the attach button and mic moved into modeControls), custom/ComposerShell.tsx, custom/voice/ForkDictationControl.tsx, theme.custom.css, comments in ComposerPrimaryActions.tsx, and the three guard tests plus .fork/customizations.yaml updated for the new placement. Rebased onto the current custom, which includes the orchestrator-V2 sync.

Verified: fork guards and the ComposerPrimaryActions tests pass (513), plus web typecheck, lint and format. Not checked in a running app, and no screenshots attached.

🤖 Generated with Claude Code

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	5.0 KiB	5.0 KiB	0 B (0.0%)	6.8 KiB	✅
Codex	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Codex	Live turn WebSocket wire	1.2 KiB	1.2 KiB	0 B (0.0%)	2.0 KiB	✅
Codex	Live turn WebSocket decoded	20.9 KiB	20.9 KiB	0 B (0.0%)	29.3 KiB	✅
Codex	Live turn messages	2	2	0 (0.0%)	8	✅
Claude	Total thread wire	5.0 KiB	5.0 KiB	0 B (0.0%)	6.8 KiB	✅
Claude	Thread snapshot wire	3.8 KiB	3.8 KiB	0 B (0.0%)	4.9 KiB	✅
Claude	Live turn WebSocket wire	1.2 KiB	1.2 KiB	0 B (0.0%)	2.0 KiB	✅
Claude	Live turn WebSocket decoded	21.2 KiB	21.2 KiB	0 B (0.0%)	29.3 KiB	✅
Claude	Live turn messages	2	2	0 (0.0%)	8	✅

Baseline: d43b2e6 · PR result: c4f305d · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 108.5 KiB
• Claude decoded thread snapshot: 108.8 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[cursor]

Thermo-nuclear on HEAD c4f305dc: no major structural issues.

The move deletes the old model. dictationOwnsPrimaryAction is now isAvailable && blocksSubmission. The leading slot, the two-column grids, the hidden ghost width-reserve, and the idle-empty / resume-yield send-slot gate are gone. Attach and the mic land in the existing left slot. Send is the only prompt-row button. Net −136. No file crosses 1k.

Do not add a ComposerShell leading prop back. Do not decompose ChatComposer / theme.custom.css / yaml.

  

_{Sent by Cursor Automation: Thermo nuke 4.6}

[NoahHendrickson]

Reviewed commit c4f305dc7f002de885cfd1ecec3045d5f27d856a.

No actionable correctness findings in this diff. I traced the moved attach/mic controls, idle versus active dictation slot ownership, resume/stop paths, pending-question and approval gates, and the draft/started-thread CSS layouts. The change applies to web and the desktop web shell; native mobile, provider adapters, RPC contracts, and connection handling are unchanged.

Validation: all 54 tests passed across forkComposerShell, forkLocalDictation, forkNewAgentDraft, and ComposerPrimaryActions, using the web app's test configuration. git diff --check also passed.

Two remaining verification caveats:

• No running-client visual pass was performed, so narrow-width layout, file-picker interaction, and live dictation geometry still need visual verification. The PR currently has no before/after screenshots.
• CI is not fully green: Test Server 4 fails in AcpSessionRuntime.processTree.test.ts, “rotates more than 64 live parents without scanning retained tombstones,” with retained processes 1084, 11084. That code is untouched by this PR; I found no connection to this composer change. Failing job.

Reviewed by GPT-6 Astra via the Codex harness.