[P1][bug] TitleBar/Toolbar duplicate the Compare/Admin/Import/Backup/Restore/Theme toolbar — drift-prone

[EVWorth]

Context

The 5 feature buttons (Compare / Admin / Import / Backup / Restore) plus the theme-cycle button appear in three places, picked by isMac at AppLayout.tsx:248-263.

Problem

Three files duplicate the toolbar buttons:

src/components/layout/TitleBar.tsx:122-170 — Windows/Linux users see this. Renders Compare, Admin, Import, Backup, Restore, conditional AI, theme-cycle.

src/components/layout/Toolbar.tsx:69-118 — macOS users see this. Renders the same 5 buttons + AI + theme-cycle.

src/components/layout/MenuBar.tsx:11-89 — has menu items for many of the same features but no theme-cycle entry at all (see #452 / F8).

The cycleTheme function is duplicated:

• Toolbar.tsx:46-50
• TitleBar.tsx:68-72

Adding a new feature button requires editing two files (TitleBar + Toolbar). Forgetting one means Mac users get a feature Windows users don't (or vice versa).

The cross-cutting audit (docs/audits/cross-cutting.md F7) flagged this as P1.

Files

• src/components/layout/TitleBar.tsx:122-170 (5 buttons + theme cycle)
• src/components/layout/Toolbar.tsx:69-118 (5 buttons + theme cycle)
• src/components/layout/MenuBar.tsx:11-89 (menu items, no theme)

Repro

grep -n "Compare\|Admin\|Import\|Backup\|Restore" src/components/layout/TitleBar.tsx | head -20
grep -n "Compare\|Admin\|Import\|Backup\|Restore" src/components/layout/Toolbar.tsx | head -20
# Same buttons, different files
grep -n "cycleTheme" src/components/layout/*.tsx
# TitleBar.tsx:68-72, Toolbar.tsx:46-50 — duplicated

Expected

A single <FeatureToolbar /> component renders the buttons. A useThemeCycle() hook exposes theme, next, cycle. Both TitleBar and Toolbar compose the FeatureToolbar.

Proposed fix

Scope M. Extract:

• src/components/layout/FeatureToolbar.tsx — { onShowImport, onShowBackup, onShowRestore, onToggleAI, aiPanelOpen, aiEnabled } props, renders the 5 buttons + AI.
• src/hooks/useThemeCycle.ts — wraps useThemeStore.getState() + the cycle index logic.
• TitleBar and Toolbar both consume <FeatureToolbar /> and <ThemeCycleButton />.

Acceptance

Adding "Open Query History" to the feature bar requires editing one component, not two. The two duplicated cycleTheme functions reduce to one hook. TitleBar.tsx and Toolbar.tsx both shrink by ~50 LOC.

Needs human verify

No (refactor only).

Labels: audit, area/cross-cutting, severity/p1, kind/bug