Containerise: Postgres + Redis/RQ + API + Ghidra worker

Brings up the documented target architecture as a docker-compose stack — a
modular monolith with the Ghidra step split into its own async worker.

- worker/: RQ queue (lazy redis import) + run_acquisition task (Job status
  queued→started→finished/failed, drives ams.acquire with sink=db)
- Job model + JobOut schema; Snapshot.data is JSONB on Postgres
- POST/GET /jobs: stream an upload to a shared volume, enqueue, poll status
- docker/api.Dockerfile (slim) + docker/worker.Dockerfile (JDK21 + Ghidra
  fetched at build, overridable via GHIDRA_URL) + docker-compose.yml
- ghidra.py: AMS_GHIDRA_SCRIPTS override for in-container script path
- pyproject: [worker] extra (rq/redis/psycopg), python-multipart in [api]
- tests: 4 new (task success/failure + endpoint enqueue/503) -> 22/22

Verified: API image builds, container serves /health + /ui + /jobs; compose
config validates. Worker image (downloads ~1 GB Ghidra) not built here.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ams/acquire/ghidra.py

@@ -63,7 +63,7 @@ def run_extractor(
         raise GhidraNotFound(
             "analyzeHeadless not found — set $GHIDRA_HEADLESS or $GHIDRA_HOME (Ghidra's install dir)")
 
-    script_dir = script_dir or str(_SCRIPT_DIR)
+    script_dir = script_dir or os.environ.get("AMS_GHIDRA_SCRIPTS") or str(_SCRIPT_DIR)
     out_path = os.path.abspath(out_path)
     os.makedirs(os.path.dirname(out_path) or ".", exist_ok=True)