Goal

Rewrite the Settings surface end-to-end (frontend + code) to match the two-layer takeover design preview, replacing the current tab-router layout. Remove legacy toggles and dead code along the way.

This issue body was originally framed as an audit-first incremental refactor. After ground-truth check against the design preview, that frame was retired — see the v4 plan comment for the pivot rationale.

Scope

In scope:

• New settings shell: two-layer takeover, 240px nav, 7 nav items.
• 7 sub-pages (some new, some carrying business logic forward from existing files): General · Keybinds · AI · Remote access · Integrations · Worktrees · Memory.
• Deletion of obsolete settings-*.tsx files, the right-panel Connections tab, and the sound effects subsystem (including audio assets).
• Migration of LSP master toggle from General to Integrations.
• Migration of right-panel Connections content (Servers / MCP / LSP / Plugins) into Settings.Integrations.
• Removal of shellToolPartsExpanded / editToolPartsExpanded settings; per-tool default fold for bash / edit preserved via grouping.ts hard-coded return false.
• Removal of settings-general.tsx L299-325 commented-out WSL block and related dead i18n keys.

Out of scope:

• Keybinds detailed UI redesign (use a minimal pass; visual rebuild deferred).
• Worktrees + Memory visual rebuild (business logic preserved; visual refresh deferred).
• [Feature] Expose granular permission configuration in Settings, with smarter defaults #259 granular permission GUI (auto-accept binary toggle stays in General; [Feature] Expose granular permission configuration in Settings, with smarter defaults #259 ships separately).
• [Feature] Skill management GUI in the desktop app #220 Skill management GUI (can land as a future Integrations sub-section).
• Session-level "what tools / MCP / LSP this session used" view (YAGNI).
• Appearance page (dropped entirely — theme switching not yet enabled).

Relevant context

Parent: #599

Files to reference for business-logic preservation (will be rewritten or deleted, not refactored):

• packages/app/src/components/settings-general.tsx
• packages/app/src/components/dialog-connect-provider.tsx (+ 7 already-extracted siblings)
• packages/app/src/components/dialog-select-server.tsx (+ 4 already-extracted siblings)
• packages/app/src/components/session/session-status-connections.tsx
• packages/app/src/context/settings.tsx

Closed by this issue:

• [Task] Decide right-panel Connections section position (move to Settings or keep, alert channel needed) #862 (Connections section position) — Connections tab removed; content merged into Settings.Integrations.

Verification

• bun typecheck clean.
• bun test clean.
• bun test packages/app/e2e clean — settings shell + 7 nav routing covered; right-panel no longer has Connections tab.
• bun run dev:desktop manual walk — single bash tool defaults to folded; single grep tool defaults to expanded; LSP master in Integrations actually disables LSP.
• bun run snap settings — new snap target added for shell + 7 sub-pages; PNG attached to PR.
• Linux Wayland — verified locally if possible, otherwise note CI screenshot dependency in PR.

Execution mode

Single hard-cutover PR (~25 files touched, ~400 lines deleted net). Plan v4 is in this comment. Soft-transition fallback (feature flag, old + new coexist) is available if the PR proves too heavy in review.