Task: Investigate and fix the first-open work preview layout

Identity

Task ID: 20261008-work-first-open-8ac7e621
Mode: Feature
Branch: codex/20261008-work-first-open-8ac7e621-work-first-open
Worktree: /Users/chillishark/Makelore 麦洛/.codex-worktrees/makelore/20261008-work-first-open-8ac7e621
Base commit: fe1a3775c5
Owner: codex
Status: Ready for Integration

Fix the first-open Work preview being pushed below the entire teacher welcome group. Renderer visibility only; preserve native-preview overlay clearance for real messages and hover introductions.

User confirmed: temporarily hide welcome introductions on Work, restore on Operation Chat. Do not persist dismissal or change the three-operation-round introduction lifecycle, unread receipts, consultation entry, or preview startup.
No running-app update, main merge, push, or cleanup requested for this change.

Task context:

Task ID / mode / branch / worktree / base: exactly as Identity above; official start and status ownership verification passed.
Other local tasks: 27 peer owner records inspected by read-only reviewer through their registered paths; no active conflicting layout work.
Related completed scopes: teacher-group-intro, hover intro, preview toolbar, empty-work preview. Preserve grouped dismissal and real unread messages.

Read:

Agent entry/read-before-planning, memory-index, planning-gate; this task record.
Project positioning, current-state, decision-index, system-overview, business-rules, success-criteria (task-relevant sections).
ADR-2026-09-22-coding-teacher; evidence-index, reflection-index, commitments; AGENTS.md and README.md.

Relevant understanding:

Project goal: student creation workspace with Main-owned native Work preview and cloud-defined teachers.
Integrated baseline: fe1a377, clean main. URL toolbar beside workspace tabs; native pixels avoid teacher DOM overlays.
Root cause: bubbleRef points to the whole welcome group; usePreviewClearance offsets the whole panel below its bottom, wasting most of the first-open viewport.
Constraints: only gate welcome rendering with the current tab; keep hook/persistence, real invitations, hover descriptions, and backend contracts unchanged.
Canonical ADR still describes per-teacher introduction dismissal, superseded by the grouped implementation and README; this change preserves current grouped behavior.
Evidence: user screenshots and static code; isolated browser measurements and regressions to follow. No applicable unresolved external commitment.
Modules: TeacherCompanion, CodingChatPanel, related unit/browser/Electron fixtures and README.

Gate result: Passed.

Add a presentation-only welcome visibility prop and derive it from the Work tab.
Cover hide/restore without consuming welcome state, real messages remaining visible, first-open preview geometry, and actual workspace integration.
Run focused unit/browser/Electron checks, typecheck, lint and production build; record evidence and hand off a committed feature branch.

Added presentation-only showWelcomes to TeacherCompanion, controlled by !agentBrowserOpen. Both grouped introductions and the legacy static welcome are unmounted on Work, and return on Operation Chat if not already consumed by existing lifecycle rules.
Real invitations/unread markers and hover descriptions remain visible with existing native-preview clearance. No persistent dismissal, model call, storage change, or preview startup change is triggered by this flag.
Updated README, lifecycle unit regressions, four-size browser layout scenarios, and the existing actual Electron workspace test.
Baseline reproduced in isolation: group height 440px; native preview was pushed down 391px, from top 107px to 498px. At 1280x800, height dropped from 639px to 248px; at 1440x900, from 739px to 348px. Fixed screenshots restore top 107px and full 639/739px height.
Independent read-only review found no blocking issue, stale margin, ResizeObserver leak, or new first-open bounds race.

Typecheck, scoped ESLint, and production build:vite passed using pinned pnpm 10.33.4. Logs: /tmp/makelore-first-work-{typecheck,lint,build}.log.
Focused units: 103 cases across teacher-companion, coding-chat-panel, and agent-browser-panel. Initial parallel run passed 102 and hit an existing asynchronous presentation assertion in unchanged agent-browser-panel; that file passed all 17 alone on retry. All changed-component tests passed initially. Logs: /tmp/makelore-first-work-units.log, /tmp/makelore-first-work-browser-units-retry.log.
Browser layout suite: 18/18 passed, including 375/768/1280/1440px hide/restore, repeat visits, explicit dismissal, real messages, and hover clearance. Screenshots visually inspected; no horizontal overflow. /tmp/work-first-open-browser-8ac7e621/run.log and results/.
Electron production-build fixture: 1/1 passed, proving actual workspace tab wiring, full-height preview, hover recovery, welcome restoration, teacher entry and retained drafts. /tmp/makelore-first-work-electron.log, /tmp/makelore-first-work-electron-results/.
Baseline geometry and before/after images: /tmp/work-first-open-repro-8ac7e621/.
Tests use isolated fixtures; installed app and user project/data were not changed. No installed-app update or native game-content acceptance claimed.

Running-app update and main integration remain separate user-requested steps; feature branch is ready for handoff.

Target: teacher ADR and system-overview. Proposal: static welcome introductions are paused on Work and restored on Operation Chat without consuming introduction or unread state; actual messages and hover descriptions retain native clearance. Evidence: user explicitly selected this behavior, focused lifecycle/browser/Electron regressions. Future impact: prevents reintroducing full-panel welcome clearance on first Work entry. Conflict: older ADR intro dismissal wording is stale relative to grouped implementation; leave it read-only in this feature. Further human confirmation for this visibility behavior is not required.