Fix GlitchTip source map assembly: shared uploads volume + MEDIA_ROOT

- Mount glitchtip_uploads named volume to /code/uploads on both
  glitchtip-web and glitchtip-worker so chunk blobs written by the
  web container are readable by the worker during assembly
- Set MEDIA_ROOT=/code/uploads explicitly on both services so the
  Django storage path matches the volume mount and DB blob records

homelab/docker-compose.yml

@@ -169,6 +169,9 @@ services:
       VALKEY_URL: "redis://valkey:6379/1"
       PORT: "8000"
       ENABLE_USER_REGISTRATION: "false"
+      MEDIA_ROOT: "/code/uploads"
+    volumes:
+      - glitchtip_uploads:/code/uploads
     healthcheck:
       test: ["CMD", "python3", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:8000/api/0/')"]
       interval: 15s
@@ -190,6 +193,9 @@ services:
       DEFAULT_FROM_EMAIL: "noreply@libnovel.cc"
       VALKEY_URL: "redis://valkey:6379/1"
       SERVER_ROLE: "worker"
+      MEDIA_ROOT: "/code/uploads"
+    volumes:
+      - glitchtip_uploads:/code/uploads
 
   # ── Umami ───────────────────────────────────────────────────────────────────
   umami:
@@ -540,3 +546,4 @@ volumes:
   grafana_data:
   pocket_tts_cache:
   hf_cache:
+  glitchtip_uploads: