feat(ui): the viewer's screens as @colbymchenry/codegraph-ui, behind one adapter (CG-61)

`ui/src` now builds two ways from one tree: the static app `codegraph ui`
serves, and — via `svelte-package` — a Svelte library the Pro app imports.
A forked component would be a second answer to the same question about the
same graph, so there is no fork.

Everything a screen knows arrives through a `GraphAdapter`: eleven methods
answering the wire shapes verbatim, with `createHttpAdapter()` (the loopback
JSON API) as the default and a host's in-process engine reads as the point.
`lib/api.ts` became a one-line-per-call facade over it, which is why no call
site in the views changed. The payload types moved to `lib/wire.ts` — no
imports, no runtime — so a host can depend on the vocabulary alone.

Two more seams and one guard:

- `lib/navigation.ts` holds the href builders behind a `NavigationDriver`, so
  a host addresses its own URL space. The app's half — the hash parser and the
  live route, which attach window listeners at module scope — stays in
  `router.svelte.ts` and is pruned out of the package: rendering a Symbol view
  must not install a hash router in somebody else's application.
- `lib/theme.css` carries the design tokens and maps Svelte Flow's `--xy-*`
  variables onto them, so a host never sees library defaults. Dark now also
  answers to a bare `[data-theme]`, which is how `<CodegraphUi theme>` themes
  a container rather than the document.
- `scripts/check-ui-package.mjs` prunes the app's shell, resolves the
  extensionless specifiers svelte-package leaves behind, and asserts that
  nothing but `lib/adapter.js` reaches the network.

The search box, its keyboard and its panel are one component now
(`SearchPalette`), because splitting them is what breaks a palette.

`__tests__/ui-package.test.ts` mounts the three screens from the package entry
against a mock adapter in jsdom; it runs as a second vitest project so the
`browser` resolve condition it needs cannot reach the engine's suites.

Versioned with the engine. Prepared, not published: `private: true` is the
guard and `pack-npm.sh` only packs a tarball under CODEGRAPH_PACK_UI=1.

CLAUDE.md

@@ -12,6 +12,7 @@ Distributed as `@colbymchenry/codegraph` on npm; same binary serves as installer
 
 ```bash
 npm run build           # tsc + copy schema.sql and *.wasm + build the viewer into dist/; chmods dist/bin/codegraph.js
+npm run build:lib       # the viewer's components as @colbymchenry/codegraph-ui (ui/dist) — NOT part of `build`
 npm run dev             # tsc --watch
 npm run clean           # rm -rf dist
 
@@ -36,6 +37,22 @@ browser viewer into `dist/viewer/` (never `dist/ui/` — that's the terminal ui)
 highlighting reads a file with the same grammar the engine indexed it with, so a missing wasm is an
 unhighlighted screen as well as an extraction gap.
 
+`npm run build:lib` is separate and does NOT run as part of `npm run build`: it compiles the same
+`ui/src` tree a second way, with `svelte-package`, into `ui/dist` — the `@colbymchenry/codegraph-ui`
+component library the Pro app imports (task CG-61). `scripts/check-ui-package.mjs` then prunes the
+standalone app's shell out of it, resolves the extensionless import specifiers `svelte-package`
+leaves behind, and asserts the seam: nothing outside `lib/adapter.js` may reach the network. The
+package is **prepared, not published** — `ui/package.json` carries `"private": true` deliberately,
+and `scripts/pack-npm.sh` only packs a tarball when `CODEGRAPH_PACK_UI=1`.
+
+Tests run as **two vitest projects** (`vitest.workspace.mts`): `engine` (node) and `ui` (jsdom, the
+Svelte plugin, `resolve.conditions: ['browser']`) for the single `__tests__/ui-package.test.ts`.
+`npm test` still runs both. The split is not cosmetic — `browser` is a package-resolution
+condition, and applied globally it hands the engine's suites the browser builds of
+`web-tree-sitter` and friends. The root config (`vitest.config.mts`, `.mts` because the plugin is
+ESM-only and the repo is CJS) is the shared base; note that a workspace project **concatenates**
+the base's `include` with its own, which is why the `ui` project does not `extends` it.
+
 Node engines: `>=20.0.0 <25.0.0`. There is a hard exit on Node 25.x and below 20 (see `src/bin/node-version-check.ts`).
 
 ## Architecture