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.

scripts/pack-npm.sh

@@ -125,3 +125,29 @@ VERSION="$VERSION" SCOPE="$SCOPE" TARGETS="${targets[*]}" \
 
 echo "[pack-npm] ${SCOPE}/codegraph@${VERSION} (${#targets[@]} platform packages in optionalDependencies)"
 echo "[pack-npm] output: $NPM"
+
+# ---------------------------------------------------------------------------
+# @colbymchenry/codegraph-ui — the viewer's components as a Svelte library.
+#
+# Staged into release/npm-ui/, NOT release/npm/: the workflow publishes
+# `release/npm/codegraph-*` by glob, and a directory named codegraph-ui in
+# there would be swept into that loop the moment it existed.
+#
+# OFF by default. The package is prepared, versioned with the engine and
+# tested (CG-61), but publishing it is a decision the maintainer has not
+# made — and `ui/package.json` still carries `"private": true`, which is what
+# actually stops an accidental `npm publish`. Set CODEGRAPH_PACK_UI=1 to build
+# the tarball; publishing it additionally means removing that flag.
+# ---------------------------------------------------------------------------
+if [ "${CODEGRAPH_PACK_UI:-0}" = "1" ]; then
+  UIREL="$REL/npm-ui"
+  rm -rf "$UIREL"
+  mkdir -p "$UIREL"
+  ( cd "$ROOT" && npm run build:lib --workspace ui )
+  # `npm pack` honours "files" and works on a private package; `npm publish`
+  # does not, which is exactly the guard we want to keep for now.
+  ( cd "$ROOT/ui" && npm pack --pack-destination "$UIREL" >/dev/null )
+  echo "[pack-npm] ${SCOPE}/codegraph-ui@${VERSION} packed (not published) -> $UIREL"
+else
+  echo "[pack-npm] skipping ${SCOPE}/codegraph-ui (set CODEGRAPH_PACK_UI=1 to pack it)"
+fi