fix: address independent review findings

docs/THREAT_MODEL.md

@@ -37,6 +37,8 @@
 | Cross-project reads | project filter plus membership resolution |
 | Browser cross-origin request | exact configurable Origin allowlist |
 | Oversized request | one MiB body limit |
+| Excessive JSON nesting | pre-parse nesting limit plus guarded decoder |
+| Slow/incomplete body | five-second application read timeout |
 | MIME confusion/caching | strict JSON input, nosniff, no-store |
 | SQL injection | parameterized SQL; one controlled placeholder expansion |
 
@@ -57,8 +59,10 @@ fetched or executed by the bus.
 4. The event payload is not cryptographically chained or signed. Add hash
    chaining/signatures only if the agreed threat model requires tamper
    evidence against privileged database operators.
-5. No application rate limiter exists. Apply per-identity limits and request
-   quotas at the trusted edge.
+5. No application rate limiter or bounded worker pool exists. The application
+   closes incomplete request bodies after five seconds, but production ingress
+   must additionally enforce connection limits, header/body read deadlines,
+   per-identity limits, and request quotas.
 6. The server emits access metadata but no security audit sink or metrics.
    Integrate structured logs, alerts, and privacy-aware retention.
 7. Membership deactivation and credential revocation are not exposed as MVP
@@ -80,4 +84,3 @@ fetched or executed by the bus.
 - review log contents for sensitive project data;
 - add abuse limits and operational monitoring;
 - decide whether privileged-operator tamper evidence is required.
-