feat(billing): plan taxonomy reconciliation + Stripe sync + internal-tester allowlist (#164)

Co-authored-by: Michael Chihlas <michael@resolutionflow.com>
Co-committed-by: Michael Chihlas <michael@resolutionflow.com>

backend/app/api/deps.py

@@ -64,6 +64,40 @@ async def get_current_user(
     return user
 
 
+async def get_current_user_optional(
+    request: Request,
+    db: Annotated[AsyncSession, Depends(get_admin_db)],
+) -> Optional[User]:
+    """Best-effort current user for endpoints that work both anonymous and authed.
+
+    Returns None on missing/invalid/expired token instead of raising. Used by
+    surfaces like /config/public that anonymous clients can hit but where an
+    authenticated user gets a tailored response (e.g. INTERNAL_TESTER_EMAILS
+    allowlist override).
+    """
+    auth_header = request.headers.get("Authorization") or request.headers.get("authorization")
+    if not auth_header or not auth_header.lower().startswith("bearer "):
+        return None
+    token = auth_header.split(None, 1)[1].strip()
+    if not token:
+        return None
+
+    payload = decode_token(token)
+    if payload is None or payload.get("type") != "access":
+        return None
+
+    user_id = payload.get("sub")
+    if user_id is None:
+        return None
+    try:
+        user_uuid = UUID(user_id)
+    except ValueError:
+        return None
+
+    result = await db.execute(select(User).where(User.id == user_uuid))
+    return result.scalar_one_or_none()
+
+
 async def get_refresh_token_payload(
     token: Annotated[str, Depends(oauth2_scheme)]
 ) -> dict: