fix(resolver): dedupe override.yml; apply gpu_backends filter to user-extensions

Two resolver-layer defects fixed together because they cluster in
the same call chain.

1. installers/lib/compose-select.sh double-appended
   docker-compose.override.yml to COMPOSE_FLAGS. scripts/resolve-
   compose-stack.sh already appends it once when its env output is
   consumed by compose-select.sh's load_env_from_output. Removing
   the redundant bash-level append leaves the resolver as the single
   source of truth.

2. scripts/resolve-compose-stack.sh included every
   data/user-extensions/<id>/compose.yaml unconditionally, bypassing
   the gpu_backends compatibility check that the built-in extension
   loop already performs. An NVIDIA-only user extension installed on
   AMD/Apple would be merged into the stack and fail at container
   start. This adds the same manifest read + schema_version +
   gpu_backends filter the built-in loop uses, verbatim, including
   "all"/"none" sentinels and the narrow-dispatch error handling
   gated by skip_broken.

Author: yasinBursali

dream-server/installers/lib/compose-select.sh

@@ -102,12 +102,5 @@ resolve_compose_config() {
         log "Including docker-compose.tier0.yml (Tier 0 memory limits)"
     fi
 
-    # Auto-include docker-compose.override.yml if present (standard Docker convention).
-    # This lets modders add services without editing core compose files.
-    if [[ -f "$SCRIPT_DIR/docker-compose.override.yml" ]]; then
-        COMPOSE_FLAGS="$COMPOSE_FLAGS -f docker-compose.override.yml"
-        log "Including docker-compose.override.yml (user overrides)"
-    fi
-
     log "Compose selection: $COMPOSE_FLAGS"
 }

dream-server/scripts/resolve-compose-stack.sh

@@ -223,10 +223,56 @@ if ext_dir.exists():
 # Discover enabled user-installed extensions (from dashboard portal)
 user_ext_dir = script_dir / "data" / "user-extensions"
 if user_ext_dir.exists():
+    try:
+        import yaml
+        yaml_available = True
+    except ImportError:
+        yaml_available = False
+
     try:
         for service_dir in sorted(user_ext_dir.iterdir()):
             if not service_dir.is_dir():
                 continue
+            # Find manifest
+            manifest_path = None
+            for name in ("manifest.yaml", "manifest.yml", "manifest.json"):
+                candidate = service_dir / name
+                if candidate.exists():
+                    manifest_path = candidate
+                    break
+            if not manifest_path:
+                continue
+            try:
+                with open(manifest_path) as f:
+                    if manifest_path.suffix == ".json":
+                        manifest = json.load(f)
+                    elif yaml_available:
+                        manifest = yaml.safe_load(f)
+                    else:
+                        continue  # skip YAML manifests when PyYAML unavailable
+                if manifest.get("schema_version") != "dream.services.v1":
+                    continue
+                service = manifest.get("service", {})
+                # same gpu_backends filter as built-in loop
+                backends = service.get("gpu_backends", ["amd", "nvidia"])
+                if gpu_backend not in backends and "all" not in backends and "none" not in backends:
+                    continue
+            except Exception as e:
+                yaml_error = yaml_available and hasattr(yaml, 'YAMLError') and isinstance(e, yaml.YAMLError)
+                json_error = isinstance(e, json.JSONDecodeError)
+                structure_error = isinstance(e, (KeyError, TypeError))
+
+                if yaml_error or json_error or structure_error:
+                    print(f"ERROR: Failed to parse manifest for {service_dir.name}: {e}", file=sys.stderr)
+                    print(f"  Manifest path: {manifest_path}", file=sys.stderr)
+                    print(f"  This service will be skipped. Fix the manifest or disable the service.", file=sys.stderr)
+                    if skip_broken:
+                        continue
+                    else:
+                        sys.exit(1)
+                else:
+                    raise
+
             compose_path = service_dir / "compose.yaml"
             if compose_path.exists():
                 resolved.append(str(compose_path.relative_to(script_dir)))