fix(security): harden API against pentest findings

- Default TRUST_PROXY=false to prevent XFF rate limit bypass (PT-01)
- Return 400 instead of 500 on malformed JSON input (PT-03)
- Default MAX_PIPELINE_STEPS=20 to prevent DoS (PT-04)
- Validate clientJobId length (max 128) across all routes (PT-06)
- Add security headers to all reply.hijack() streaming responses (PT-07)
- Sanitize usernames in audit log to prevent stored XSS (PT-08)
- Block TRACE method with 405 response (PT-10)
- Add 429 RateLimited response to OpenAPI spec (PT-12)
- Default MAX_SVG_SIZE_MB=50 to limit SVGZ decompression (PT-13)
- Pin Dockerfile base images by digest
- Sanitize OIDC IdP error and sub claim in audit log
- Sync Docker compose/Dockerfile defaults with env.ts

apps/api/src/routes/progress.ts

@@ -11,6 +11,7 @@
 import { eq } from "drizzle-orm";
 import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
 import { db, schema } from "../db/index.js";
+import { getSecurityHeaders } from "../lib/csp.js";
 
 export interface JobProgress {
   jobId: string;
@@ -230,6 +231,7 @@ export async function registerProgressRoutes(app: FastifyInstance): Promise<void
         "Cache-Control": "no-cache",
         Connection: "keep-alive",
         "X-Accel-Buffering": "no",
+        ...getSecurityHeaders(),
       });
 
       // Helper to send an SSE message