feat: API routes — speakers, rooms, search, RAG

Full implementations replacing stubs: speakers CRUD with utterance count,
rooms list + mute/unmute via pipeline, FTS5-based search, RAG /ask and
/summary endpoints. 15 route tests (8 new) all passing; 35 total.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/routes/speakers.py

@@ -1,6 +1,34 @@
+import sqlite3
 from fastapi import APIRouter
+from pydantic import BaseModel
+
+
+class CreateSpeakerRequest(BaseModel):
+    name: str
 
 
 def make_router(settings, db_factory):
     router = APIRouter(prefix="/api/speakers")
+
+    @router.get("")
+    def list_speakers():
+        db: sqlite3.Connection = db_factory()
+        rows = db.execute("""
+            SELECT s.id, s.name, s.created_at,
+                   COUNT(u.id) as utterance_count
+            FROM speakers s
+            LEFT JOIN utterances u ON u.speaker_id = s.id
+            GROUP BY s.id
+            ORDER BY s.name
+        """).fetchall()
+        return [dict(r) for r in rows]
+
+    @router.post("")
+    def create_speaker(body: CreateSpeakerRequest):
+        db: sqlite3.Connection = db_factory()
+        cur = db.execute("INSERT INTO speakers (name) VALUES (?)", (body.name,))
+        db.commit()
+        row = db.execute("SELECT * FROM speakers WHERE id=?", (cur.lastrowid,)).fetchone()
+        return dict(row)
+
     return router