stt leaves the platform for the transcribe plugin

Speech-to-text is now plugins/transcribe — sidecar, its own config, its own
skill and a task for the file browser's context menu. The transcription logic
moved BYTE FOR BYTE: 416 lines whose every decision has a reason attached, from
the two-pass detect-then-transcribe to the 25 language priming prompts to
timeout:false. Verified identical rather than assumed.

Removed here: api/stt/, server-settings/stt.ts and its mount, POST /chat/stt,
POST /file-browser/transcribe, the FileViewer handler behind the button hidden
last release, the Settings screen, the dead useAudioRecording hook and the
orphaned locale keys across all six locales.

blobToWav stayed. It lived in the same file as the dead hook and is still used
by DictateDialog — unrelated to STT, and deleting by file rather than by use is
how that would have gone.

No permission entry to remove: STT never had one, living under server-admin,
chat and files. The registry count is unchanged and docs:check is green.

The plugin ships a task that will not appear in the menu yet — the platform
loads a plugin's skills, affordances and notifications from its own directory
but not its tasks. That loader is the remaining piece of docs/plugin-capabilities.md
and is deliberately not built here.

1426 pass, tsgo clean, 18 plugins discovered with none broken.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: 656f5c85-e49a-4f1f-b9f3-042a04b4d043

src/servers/api/chat/chat.ts

@@ -5,7 +5,6 @@ import { createRouter } from '../../create-router';
 import * as errors from '@@/custom-errors';
 import * as sidecar from '@@/sidecar-registry';
 import {
-  getUserSettings,
   getChatSessionModel,
   getChatSessionModels,
   listCommandHqSessionIds,
@@ -45,7 +44,6 @@ import type { ChatIdentity } from './claude-sessions';
 import { officerModelForApiModel } from './model-aliases';
 import { readAccountEmail } from './claude-usage';
 import { listStoredUsage, mergeUsage, snapshotClaudeUsage } from './usage-store';
-import { readSttConfig } from '../server-settings/stt';
 
 /**
  * Whose transcripts a request may read.
@@ -81,7 +79,6 @@ export async function chatIdentity(user: { id: number; email: string }): Promise
 // identity the way `spawnClaudeAsMember` does. Restrict here rather than at the permission layer because
 // `chat` is one permission covering both harnesses, and splitting it would strand the grants already issued.
 // The matching refusal on the execution path is in `websocket.ts` → `handleChat`.
-import { transcribeAudio } from '../stt/transcribe';
 import { registerAgentPanelRoutes } from './agent-panels-routes';
 
 export const chatRouter = createRouter();
@@ -629,32 +626,6 @@ chatRouter.get('/models', async (ctx: Context) => {
   }
 });
 
-// POST /chat/stt — proxy an audio clip to the configured Whisper server.
-chatRouter.post('/stt', async (ctx: Context) => {
-  const sttConfig = await readSttConfig();
-  if (!sttConfig?.url) {
-    return ctx.json({ error: 'Whisper not configured — set it up in Settings → Speech to Text' }, 400);
-  }
-
-  const user = ctx.get('user');
-  const body = await ctx.req.parseBody();
-  const file = body['file'];
-  if (!file || !(file instanceof File)) {
-    return ctx.json({ error: 'file is required' }, 400);
-  }
-
-  const settings = (await getUserSettings(user.id)) as { languages?: { spoken?: string[] } };
-  const spokenLanguages = settings.languages?.spoken ?? [];
-
-  try {
-    const result = await transcribeAudio({ file, whisperUrl: sttConfig.url, spokenLanguages });
-    return ctx.json(result);
-  } catch (err) {
-    logger.error('STT proxy failed', { error: String(err) });
-    return ctx.json({ error: err instanceof Error ? err.message : 'Failed to reach Whisper server' }, 502);
-  }
-});
-
 // The agent address book — naming a chat panel so other agents on the same dashboard can reach it.
 // Lives on this router because it is the same authority `chat` already grants: creating and naming
 // Claude sessions. See servers/api/chat/agent-panels-routes.ts and docs/agent-coordination.md.