fix(diarization-ui): have _job_get return dict instead of sqlite3.Row

sqlite3.Row does not support .get() — converting to dict at the source
fixes all current and future call sites uniformly.

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

app.py

@@ -280,7 +280,8 @@ def get_prompts():
 
 def _job_get(job_id: int):
     with db() as c:
-        return c.execute("SELECT * FROM jobs WHERE id=?", (job_id,)).fetchone()
+        row = c.execute("SELECT * FROM jobs WHERE id=?", (job_id,)).fetchone()
+        return dict(row) if row else None
 
 
 def _job_set(job_id: int, **fields):
@@ -348,7 +349,7 @@ def _process_analysis_job(job_id: int):
         if not doc or not prm:
             raise RuntimeError("Dokument oder Prompt nicht gefunden")
 
-        user_extra = (j["user_prompt"] or "").strip() if j["user_prompt"] is not None else ""
+        user_extra = (j.get("user_prompt") or "").strip()
         llm_prompt = (
             "Du bist ein präziser Assistent. Antworte auf Deutsch.\\n"
             f"AUFTRAG:\\n{prm['prompt']}\\n"