feat(ui): three-page console SPA on @unom/ui + the kit's react helpers

Overview (exporter health, Playnite version, counts, sync, live SSE activity,
and a first-run panel that names the exact ingest path the .pext writes to),
Library (covers + per-game include toggles + why-not-synced), Settings
(filters, art delivery, sync cadence, paths).

Data layer is AtomHttpApi atoms derived from the shared contract; the whole
thing runs with zero host against an in-browser mock transport with four
scenarios, and Storybook renders the real pages on the same fixtures. CI now
asserts the production bundle carries no fixture strings.

Also: CI rebuilt for the workspace layout (one root install, per-package
typecheck, publish from plugin/ on a v* tag) with the exporter job and
`publish: needs [build, exporter]` unchanged; README rewritten around the three
workspaces, with the ingest inbox explained as the load-bearing mechanism it is.

exporter/README.md

@@ -17,7 +17,7 @@ On startup, on every `OnLibraryUpdated`, and (debounced) on any per-game add/upd
 %APPDATA%\Playnite\ExtensionsData\<plugin-guid>\punktfunk-library.json
 ```
 
-Shape (kept in lockstep with `../src/export-schema.ts`):
+Shape (kept in lockstep with `../contract/src/export.ts`):
 
 ```jsonc
 {