Titlebar chrome: one home per surface (vault drawer · Work Column · status popover)

Acceptance criteria

Machine-checked (from spec spec-20260801-chrome-one-home-per-surface):

• store_mirror_effects == 0 — no createEffect mirrors between the vaultPanel and reviewPanel stores remain
• vault_sidepanel_hosts == 0 — vault tab trigger/content blocks deleted from session-side-panel.tsx
• popover_magic_shift == 0 — no occurrences of shift={-168}
• i18n_missing_keys == 0 — new keys in all 17 locales as English fallbacks (strict parity test)
• button_flow_e2e_passing >= 3 — Playwright three-button flows across home, new-session, and session routes

Behavioral invariants (prose by design):

• Vault button opens the populated drawer on home, new-session, AND session routes (fallback to first healthy server when none is focused)
• Zero-mount drawer shows an attach-vault CTA routing to the status popover's connections tab; fetch failures show a named error + retry (nothing silent)
• Sidebar-right toggles a single-pane Work Column; its pressed state always matches the screen (single store writer)
• Clicking a changed file opens its diff as a full-column-width file tab; no sidebar+content split renders in the column at any width
• Column default width ~320px with the existing resize handle retained
• Status popover body contents unchanged (health + MCP/LSP + vault mounts + connections)

Key decisions

• Vault host: standalone drawer, every route — the session side-panel tab is retired, not repaired.
• Column composition: Changes (default) / Context / file tabs; the unlabeled icon tab becomes honest or goes away.
• Diff viewing: full-column-width file tabs via the existing tab mechanism.
• Data contract (drawer): GET /amicode/vaults and GET /amicode/vault-files consumed with a fallback-server key; empty and error are first-class states, not absences.

Constraints & invariants

• session-side-panel.tsx is merge-hot: keep the diff surgical; the deleted mirror effects must not be resurrected on the next upstream sync (see ADR).
• Test suites run with env -u OPENCODE_CONFIG_CONTENT -u OPENCODE_SERVER_PASSWORD bun test.

Prior art

• ADR docs/adr/0001-one-home-per-chrome-surface.md (this repo) — the durable why.
• amicode#174 (status popover trigger/dot split), amicode#203 (home chrome redesign), Kate 2026-07-27 (vault tab replaced git review).

Source

Designed in an Amicode grilling session 2026-08-01 ("Fixing buggy buttons in Amicode build") from user-reported symptoms + code forensics; screenshot evidence: two-pane review squish, mystery icon tab, no-git empty state. Spec review: approved-mechanical (tier-1 lenses clean; no judgment critic available).

Notes

• The circular indicator near the buttons is the context-usage ring — not a spinner, not a bug.
• Non-git projects keep upstream's "Create Git repository" empty state in the Changes tab.