feat(gui-extensions): add typed composition and lifetime primitives - #52868

…and lifetime primitives

Phase 2 of the extension SDK overhaul.

- Every built-in declares provides / uses / requires / stores and reads dependencies as Live values; actions that need an optional dependency answer while it is inactive.
- About 88 raw effects replaced: createActive for side work per provider generation or identity, memos for derived values, createLatest for async data, createVisitState for per-visit state, handlers for user intent.
- Review and summary state live in declared stores (same keys and legacy imports); session-store writes made before load are queued; session stores keep their own session identity.
- Layout.sidebar.opened() replaces review's mirrored sidebar preference; Remote.ref declares a remote by id with type-only imports, so the browser's pane remote adds no schemas to startup.
- src/renderer.ts and src/main.ts export Extension.compose; builtins.typecheck.ts fails to compile when a renderer remote has no main provider; the graph test covers every declared optional edge.
- Deprecated shapes and Live.legacy are removed, and oxlint bans createEffect, createRenderEffect and createComputed in extension code outside src/sdk.
- Solid computations created without an owner in tab-popover and the composer editor are created under their component; the btw keeper fails on the warning.

Remote becomes Ipc (IpcProvider for what main holds), Service becomes Contract, Host becomes HostApi, Native becomes Desktop, Surfaces becomes Embeds, the Link, Menu, Menubar, Status and Setting points become LinkHandler, MenuItem, MenubarItem, TitlebarItem and SettingsPage, createActive becomes createKeyed, SessionView becomes MountedSession, MainStorage becomes Storage, MainServer becomes ServerEndpoint and Store.app becomes Store.global. The renderer App splits into Build, Locale, Appearance, Router, Keybinds, Servers and Workspaces; main's MainApp into Build, Servers, Lifecycle and Log. Host files and identifiers follow the SDK names, and app code calls the side and dock open state a region. Stored keys, DOM ids and copy are unchanged.

…al shapes

Host APIs are lazy properties on the setup context and useExtension() (ctx.layout, ctx.storage, ctx.build, ...); ctx.use is removed and declared dependencies are read only through ctx.uses and ctx.requires, with ctx.uses.pane.load for Ipc.ref. Layout.open takes { tab, background }; PanelTab uses pinned, draggable and closable flags. Build has one shape in both processes and main's endpoints API is ServerEndpoints. Each process has one teardown and one signal (onCleanup and ctx.signal in the window, ctx.scope in main). Main storage returns Persisted. System.open becomes System.openExternal and the shell.bottom slot becomes window.bottom. IPC channels, payload fields and the browser embed event use the SDK names. Stored keys, DOM ids and copy are unchanged.

…to their owners

- The summary extension is now details (command details.toggle) and usage is now context (panel key context:main). Stored state, keybinds and panel keys migrate from every older id, and a migration test table proves each mapping.
- The Preferences host API is removed. The updater owns releaseNotes and What's New (seen versions migrate from highlights.v1); review owns mobile diff wrap through a SettingsPage section in the general page. Both import once from settings.v3 and render in the same place with the same copy.
- PanelTab.transient names the launcher behaviour; closable only chooses the close button.
- Persisted.update applies a returned value in both processes, and main stores a decoded copy.
- storage.remove no longer lets a store re-import from its from source.
- Store from accepts a list of older keys.
- windows-menu.tsx creates its computations under its component owner.

Pins when the dialog shows, paging, media, Get started, Don't show these in the future, the failed-request retry, and the upgrade rows for highlights.v1 and settings.v3 releaseNotes.

Every exported SDK declaration, member, option field and parameter has TSDoc, and script/sdk-docs.ts (run by bun run lint) fails on a missing one, a stale @PARAM, an unknown ctx member in the guide, or a guide code block that differs from src/example. README.md is the author guide; src/example is a small two-process extension that CI typechecks and tests and that never ships. AGENTS.md is rewritten for the final API.

The extension graph matrix, the real-host extension tests, the example extension and the browser pane tests live in packages/app/component-tests and ran only locally.

- Provides are readable through ctx.uses without a second declaration; conflicting keys are compile errors.
- MountedSession retains one session's identity and data. Screen-wide files, comments and composer live under ctx.screen.current(), which explicitly follows the route.
- Reactive panel and slot inputs receive new sessions without extra remounts. Session stores no longer need to pin route-following identities.
- MenuItem is discriminated by menu. Dialogs.open returns its own close handle. Host APIs return defaults and queue writes before the interface mounts.
- Store.main declares main-process stores alongside window stores, with typed legacy sources and process-specific ctx.stores.
- Remove the unused app slot, honor every file-search option, and allow informational titlebar items without actions.
- Keep the browser picker on the routed session and abandon pending btw questions when leaving it.
- Update the author guide, example, TSDoc and contract tests together.

Remove the non-shipped example extension and its test. The guide walks through pairing and other built-ins, with code blocks checked against their source declarations.

A dialog opened during startup now waits for the app interface, like other early host writes. This keeps What's New above a restored Settings screen and keeps keyboard focus inside it. Closing a waiting dialog cancels it.

Give a moved session a new MountedSession for its new directory, cancel dialogs closed before their deferred open, bind session stores to the live session ref, keep older store homes readable when a pick finds nothing, and import main storage from the first source the schema accepts.

…sion stores

Attach host APIs only once every extension has settled and the routes render, so early writes and dialogs land after the interface's first render. Keep the routed session's stores and stores no tab has listed yet when pruning closed tabs. Report ctx.screen as unavailable in extension stories.

The pull_request event's base SHA can predate the base branch commits GitHub merges into the checked-out ref, so lint:changed counted upstream edits as the pull request's. Diff against the merge commit's first parent instead.