Fix BMad adversarial security review findings

Resolves 11 of the 13 findings:
- [CRITICAL] SQLi in RLS: replaced SET LOCAL with parameterized set_config()
- [CRITICAL] Rate Limiting: installed and registered @fastify/rate-limit in all 5 apps
- [CRITICAL] Invite Hijacking: added email verification check to invite lookup
- [HIGH] Webhook HMAC: added Fastify rawBody parser to fix JSON.stringify mangling
- [HIGH] TOCTOU Race: added FOR UPDATE to invite lookup
- [HIGH] Incident Race: replaced SELECT/INSERT with INSERT ... ON CONFLICT
- [MEDIUM] Grafana Timing Attack: replaced === with crypto.timingSafeEqual
- [MEDIUM] Insecure Defaults: added NODE_ENV production guard for JWT_SECRET
- [LOW] DB Privileges: tightened docker-init-db.sh grants (removed ALL PRIVILEGES)
- [LOW] Plaintext Invites: tokens are now hashed (SHA-256) before DB storage/lookup
- [LOW] Scrypt: increased N parameter to 65536 for stronger password hashing

Note:
- Finding #4 (Fragmented Identity) requires a unified auth database architecture.
- Finding #8 (getPoolForAuth) is an accepted tradeoff to keep auth middleware clean.

products/05-aws-cost-anomaly/src/data/db.ts

@@ -14,7 +14,7 @@ export async function withTenant<T>(tenantId: string, fn: (client: pg.PoolClient
   const client = await pool.connect();
   try {
     await client.query('BEGIN');
-    await client.query(`SET LOCAL app.tenant_id = '${tenantId}'`);
+    await client.query('SELECT set_config($1, $2, true)', ['app.tenant_id', tenantId]);
     const result = await fn(client);
     await client.query('COMMIT');
     return result;