Pinscope open-source core

Agentic schematic validation: datasheet extraction via Claude Console
Skills, netlist/BOM design graph, per-IC direct datasheet review with
page citations, capacitor derating, Next.js report UI.

Extracted from the Pinscope cloud codebase. Auth and billing live in the
private gateway repo behind stable seams (billing_hook.py, adapter files
listed in CLAUDE.md).

backend/routers/deps.py

@@ -0,0 +1,37 @@
+"""Shared dependencies for FastAPI routers."""
+
+from __future__ import annotations
+
+from fastapi import HTTPException, Request
+
+from backend.services import projects as proj_svc
+from backend.services.storage import StorageBackend
+
+
+def get_storage(request: Request) -> StorageBackend:
+    return request.app.state.storage
+
+
+def get_user_id(request: Request) -> str:
+    return request.state.user_id
+
+
+async def resolve_or_404(request: Request, project_id: str) -> tuple[str, proj_svc.ProjectMeta]:
+    """Resolve project access (owner, collaborator, or admin) or raise 404."""
+    storage = get_storage(request)
+    user_id = get_user_id(request)
+
+    # 1. Try normal access — cheap, no external API call
+    result = proj_svc.resolve_project_access(storage, user_id, project_id)
+    if result:
+        return result
+
+    # 2. Admin fallback — Clerk API call only when normal access fails
+    from backend.routers.admin import is_admin
+
+    if await is_admin(request):
+        result = proj_svc.find_project_any_user(storage, project_id)
+        if result:
+            return result
+
+    raise HTTPException(404, "Project not found")