Merge feat/vocabulary-hint: names-and-terms decoder prompt (spec 001 workstream 2)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

# Conflicts:
#	docs/Architecture.md
#	docs/Decisions.md
#	docs/WorkBreakdown.md
#	server-py/sidecar.py
#	src/App.tsx
#	src/server/live.ts
#	src/server/transcribe.ts
#	tests/fixtures/fake_sidecar.py
#	tests/transcribe.test.ts

src/server/transcribe.ts

@@ -26,6 +26,7 @@
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import type { TranscribeStreamLine } from "../lib/engine";
+import { HINT_MAX_CHARS, normalizeHint } from "../lib/hint";
 import { getFasterWhisperModel } from "../lib/models";
 import type { TranscriptChunk, WhisperTask } from "../worker/protocol";
 import { getSessionUser as appGetSessionUser, type SessionUser } from "./auth.ts";
@@ -52,6 +53,11 @@ export interface SidecarTranscribeRequest {
    * chunks. "live": short server-live passes — sequential, no VAD (D-WS5a).
    */
   mode?: SidecarMode;
+  /**
+   * Normalized "Names and terms" hint (D-WS2a); the sidecar truncates it to
+   * Whisper's prompt budget with faster-whisper's own tokenizer.
+   */
+  prompt?: string;
 }
 
 export type SidecarMode = "file" | "live";
@@ -273,6 +279,7 @@ export function createSidecar(command?: readonly string[]): Sidecar {
             language: request.language ?? null,
             task: request.task ?? "transcribe",
             mode: request.mode ?? "file",
+            prompt: request.prompt ?? null,
           });
         } catch (error) {
           pending.delete(id);
@@ -332,18 +339,23 @@ interface TranscribeParams {
   fasterWhisperModel: string;
   language?: string;
   task: WhisperTask;
+  prompt?: string;
 }
 
 /**
- * Parse + validate the `language`/`task` query params shared by both the
- * HTTP (`POST /api/transcribe`) and WebSocket (`GET /api/transcribe/live`,
+ * Parse + validate the `language`/`task`/`prompt` query params shared by both
+ * the HTTP (`POST /api/transcribe`) and WebSocket (`GET /api/transcribe/live`,
  * src/server/live.ts) entry points, so a live session can't forward an
  * unvalidated string into the sidecar protocol just because it skips
- * `parseParams` below. A string return is the 400 error text.
+ * `parseParams` below (D-032). A string return is the 400 error text.
+ *
+ * `prompt` is the raw "Names and terms" hint (D-WS2a): at most
+ * HINT_MAX_CHARS (the UI's textarea limit), normalized exactly as the browser
+ * worker does; empty after normalization = no prompt.
  */
 export function parseLanguageAndTask(
   url: URL,
-): { language?: string; task: WhisperTask } | string {
+): { language?: string; task: WhisperTask; prompt?: string } | string {
   const rawLanguage = url.searchParams.get("language");
   let language: string | undefined;
   if (rawLanguage !== null && rawLanguage !== "" && rawLanguage !== "auto") {
@@ -356,7 +368,13 @@ export function parseLanguageAndTask(
     return `invalid task: ${rawTask}`;
   }
 
-  return { language, task: rawTask };
+  const rawPrompt = url.searchParams.get("prompt") ?? "";
+  if (rawPrompt.length > HINT_MAX_CHARS) {
+    return `prompt too long (max ${HINT_MAX_CHARS} characters)`;
+  }
+  const prompt = normalizeHint(rawPrompt);
+
+  return { language, task: rawTask, ...(prompt && { prompt }) };
 }
 
 /** Parse + validate query params; a string is the 400 error text. */
@@ -472,6 +490,7 @@ export function createTranscribeHandlers(deps: TranscribeDeps): TranscribeHandle
                 audioPath,
                 language: params.language,
                 task: params.task,
+                prompt: params.prompt,
               },
               (segment) => {
                 chunks.push({