transmission, extracted into plugins/transmission — the platform half

Sixth extraction, straight after photos. Everything transmission now lives at
gitea.officer.dev/plugins/transmission.

Deleted, not commented: the sidecar, the api router, the Transmission app (28
files including detail/ and dialogs/), the screen, the App.tsx route pair, the
Dashboard barrel line, the usePageTitle rule, the AppRegistry wiring, the
officerdev barrel re-exports, the permission registry entry, the hono.ts import
and mount comments, and the app-store catalogue entry.

No database change: transmission owns no tables. Its connection lives in
service_connections, a core table it now depends on from outside — a real
coupling, recorded in the plugin's own PLUGIN.md rather than left to be
discovered.

── Test fixtures, repointed rather than deleted ──

Transmission was the canonical `members: 'none'` fixture — a single-tenant
daemon with no user concept — across three app-store test files. slskd has the
identical shape, so the assertions moved there. Deleting them would have
quietly dropped coverage of the no-members install path along with the plugin,
which is the same trap the vault extraction hit with `members: 'invite'`.

── Vocabulary swept, per the runbook ──

Six screens and two App.tsx comments pointed at `/photos` or `/transmission` as
the worked example of the Workspace/Panel shape. Both are plugins now, so those
pointers dangled at code no longer in the tree. Repointed at /command-hq and
/soulseek, which are core.

bunx tsgo clean. 1080 pass / 0 fail.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/servers/hono.ts

@@ -25,7 +25,6 @@ import { pluginsRouter } from './api/plugins/router';
 import { isPluginPublicPath, pluginForProtocolHeaders } from './plugins/public-paths';
 import { agentHandoffRouter } from './api/agent-handoff/router';
 // import { slskdRouter } from './api/slskd/router';
-// import { transmissionRouter } from './api/transmission/router';
 // import { invoiceshelfRouter } from './api/invoiceshelf/router';
 // import { jellyfinRouter } from './api/jellyfin/router';
 // import { walletRouter } from './api/wallet/router';
@@ -151,7 +150,6 @@ const PROTECTED_MOUNTS: [prefix: string, router: ReturnType<typeof createRouter>
   // ['/caldav', caldavRouter], // the JSON door for Officer's own calendar/contacts UI  — plugin, switched off 2026-08-13
   // ['/dav', davRouter], // app-password management (the sync door is /dav, top-level)  — plugin, switched off
   // ['/notify', notifyRouter],  // plugin — switched off 2026-08-13
-  // ['/transmission', transmissionRouter],  // plugin — switched off 2026-08-13
   // ['/invoiceshelf', invoiceshelfRouter],  // plugin — switched off 2026-08-13
   // ['/jellyfin', jellyfinRouter],  // plugin — switched off 2026-08-13
   // ['/photos', photosRouter],  // plugin — switched off 2026-08-13