Merge branch 'fix/third-review-h1-h2-m1-m6'

Third security review (docs/third-review.md) plus its remediation.

Fixed and verified:
- H1  moderator could grant admin / hard-revoke  → handler split by field
- H2  unauthenticated 2-report global blocklist  → auth + distinct reporters
      + rate limit + refused when public groups are off
- M1  registration reCAPTCHA was inert           → gate unconditional; the
      desktop client's CSP allows the widget
- M2  QUIC chat/stream handlers lagged WebRTC    → brought to parity; the QUIC
      listener is now off by default ([node] quic_enabled)
- M3  link-preview SSRF gaps                      → rate limit + port allowlist
      + connect-address re-check + decompression-bomb guard
- M4  federated peer over-trust                   → source bound to the signer,
      push capped, revocation prunes the peer's own entries, replay rejected
- M5  no CSP / security headers on the SPA        → middleware; verified against
      the live app with no violations

Withdrawn:
- M6  add_group_member accepting node tokens is deliberate (commit 0443cf8,
      the CLI invite flow). The "fix" broke that flow on the deployed hub and
      was reverted.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011pG75yGK3NthNfyjH74omG

1 files changed, 13 insertions, 4 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/api/deps.py b/packages/meshbay-hub/src/meshbay_hub/api/deps.py
index 1bf57a4..907a481 100644
--- a/packages/meshbay-hub/src/meshbay_hub/api/deps.py
+++ b/packages/meshbay-hub/src/meshbay_hub/api/deps.py
@@ -72,11 +72,21 @@ async def require_user_scope(
     return current_user
 
 
+def user_is_admin(user: User) -> bool:
+    """Admin by DB role or by the config allow-list. Use inside a handler that
+    already depends on `require_moderator` but has to draw the admin line for
+    one field (see `admin_patch_user`)."""
+    return user.role == "admin" or user.username in _admin_usernames
+
+
+def user_is_moderator(user: User) -> bool:
+    return user.role in ("moderator", "admin") or user.username in _admin_usernames
+
+
 async def require_moderator(
     current_user: User = Depends(get_current_user),
 ) -> User:
-    if current_user.role not in ("moderator", "admin") \
-       and current_user.username not in _admin_usernames:
+    if not user_is_moderator(current_user):
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN,
                             detail="Moderator access required")
     return current_user
@@ -85,8 +95,7 @@ async def require_moderator(
 async def require_admin(
     current_user: User = Depends(get_current_user),
 ) -> User:
-    if current_user.role != "admin" \
-       and current_user.username not in _admin_usernames:
+    if not user_is_admin(current_user):
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN,
                             detail="Admin access required")
     return current_user