fix: resolve 20 security vulnerabilities from comprehensive audit

Critical (1-3):
- Replace hardcoded admin credentials with secure auto-generation (seed.py)
- Enforce SECRET_KEY configuration, fail in production if missing (config.py)
- Add Zip Slip and Zip Bomb protection to all ZIP import services

High/Medium (4-9):
- Add 50MB file size limit and extension whitelist to evidence uploads
- Configure CORS origins via environment variable instead of hardcoded
- Migrate JWT storage from localStorage to HttpOnly cookies (frontend+backend)
- Add rate limiting (5/min) on login endpoint via slowapi
- Replace generic dict payloads with Pydantic schemas (mass assignment)

Medium (10-17):
- Check is_active on login to prevent disabled users from authenticating
- Sanitize exception messages in API responses (system, data_sources)
- Escape LIKE wildcards in all ilike search filters across 8 routers
- Run Docker container as non-root user (appuser)
- Make MINIO_SECURE configurable via environment variable
- Add password complexity policy (12+ chars, upper/lower/digit/special)
- Implement JWT token revocation via in-memory blacklist + reduce TTL to 15min
- Replace xml.etree with defusedxml to prevent Billion Laughs attacks

Low (18-20):
- Add security headers to Nginx (CSP, X-Frame-Options, HSTS-ready, etc.)
- Disable Swagger UI/ReDoc/OpenAPI in production
- Restrict /health endpoint to internal networks via Nginx ACL

Also: rewrite install.sh as interactive wizard for guided deployment,
fix test-from-template validation error (technique_id UUID vs MITRE ID)

frontend/src/api/auth.ts

@@ -1,25 +1,32 @@
 import client from "./client";
 import type { User } from "../types/models";
 
-interface TokenResponse {
-  access_token: string;
-  token_type: string;
-}
-
-/** Authenticate and return the access token. */
+/**
+ * Authenticate the user.
+ *
+ * The backend sets an HttpOnly cookie with the JWT — no token is stored
+ * in JavaScript memory or localStorage.
+ */
 export async function login(
   username: string,
   password: string,
-): Promise<string> {
+): Promise<void> {
   const params = new URLSearchParams();
   params.append("username", username);
   params.append("password", password);
 
-  const { data } = await client.post<TokenResponse>("/auth/login", params, {
+  await client.post("/auth/login", params, {
     headers: { "Content-Type": "application/x-www-form-urlencoded" },
   });
+}
 
-  return data.access_token;
+/** Clear the authentication cookie on the server. */
+export async function logout(): Promise<void> {
+  try {
+    await client.post("/auth/logout");
+  } catch {
+    // Best-effort — the cookie will expire anyway
+  }
 }
 
 /** Fetch the currently authenticated user profile. */