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)

docker-compose.yml

@@ -1,11 +1,9 @@
 # =============================================================================
-# Aegis - MITRE ATT&CK Coverage Platform
+# Aegis - MITRE ATT&CK Coverage Platform (Development)
 # =============================================================================
 # 
 # Quick Start:
 #   docker-compose up -d
-#   docker-compose exec backend alembic upgrade head
-#   docker-compose exec backend python -m app.seed
 #
 # Access:
 #   - Frontend:      http://localhost:5173
@@ -13,7 +11,8 @@
 #   - Swagger UI:    http://localhost:8000/docs
 #   - MinIO Console: http://localhost:9001 (minioadmin/minioadmin)
 #
-# Default credentials: admin / admin123
+# Admin credentials are auto-generated on first start — check the
+# backend container logs:  docker-compose logs backend | grep -A5 "Admin"
 # =============================================================================
 
 services:
@@ -67,8 +66,9 @@ services:
     environment:
       # Database
       DATABASE_URL: postgresql://postgres:postgres@postgres:5432/attackdb
-      # Security (change in production!)
-      SECRET_KEY: change-me-in-production-use-a-long-random-string
+      # Security — SECRET_KEY is left unset so an ephemeral key is
+      # auto-generated for local development (see backend logs for warning).
+      # Set it explicitly if you need persistent sessions across restarts.
       ALGORITHM: HS256
       ACCESS_TOKEN_EXPIRE_MINUTES: 60
       # MinIO