AGPL source offer, notices and name cleanup

Every build writes the exact tree it was built from, uncommitted work
included, as source.tar.gz next to the app, and names that tree. The sidebar,
user menu, sign-in card and version tooltip link to it.

Coffey Labs' copyright line is added below Stalwart Labs' in every inherited
file changed, and the new files carry Coffey Labs' alone.

The upgrade prompt and its links are gone, the edition tooltip is neutral,
storage keys and the package description are INBUXA's own, and the README
states the lineage once, in the fine print.

vite.config.ts

@@ -8,13 +8,18 @@ import { version } from './package.json' with { type: 'json' }
 // INBUXA's own dated version lives apart from package.json, whose version
 // follows upstream WebUI so its bumps merge without conflicts.
 import inbuxa from './inbuxa-version.json' with { type: 'json' }
+import { sourceArchive, sourceIdentity } from './source-archive'
+
+const source = sourceIdentity(import.meta.dirname)
 
 export default defineConfig({
   base: './',
   define: {
-    __APP_VERSION__: JSON.stringify(`${inbuxa.version} (WebUI ${version})`),
+    __APP_VERSION__: JSON.stringify(`${inbuxa.version} (base ${version})`),
+    // The tree this build came from; source.tar.gz next to the app holds it.
+    __SOURCE_ID__: JSON.stringify(source.id),
   },
-  plugins: [react(), tailwindcss()],
+  plugins: [react(), tailwindcss(), sourceArchive(import.meta.dirname, 'inbuxa-admin', source)],
   resolve: {
     alias: {
       '@': path.resolve(import.meta.dirname, './src'),