fix(security): implement all 15 security fixes from penetration test V1

Security audit (2026-03-31): 5 HIGH + 10 MEDIUM issues, all fixed.

HIGH:
- H1: JWT password_version mechanism (pwv in Claims, middleware verification,
  auto-increment on password change)
- H2: Docker saas port bound to 127.0.0.1
- H3: TOTP encryption key decoupled from JWT secret (production bailout)
- H4+H5: Tauri CSP hardened (removed unsafe-inline, restricted connect-src)

MEDIUM:
- M1: Persistent rate limiting (PostgreSQL rate_limit_events table)
- M2: Account lockout (5 failures -> 15min lock)
- M3: RFC 5322 email validation with regex
- M4: Device registration typed struct with length limits
- M5: Provider URL validation on create/update (SSRF prevention)
- M6: Legacy TOTP secret migration (fixed nonce -> random nonce)
- M7: Legacy frontend crypto migration (static salt -> random salt)
- M8+M9: Admin frontend: removed JS token storage, HttpOnly cookie only
- M10: Pipeline debug log sanitization (keys only, 100-char truncation)

Also: fixed CLAUDE.md Section 12 (was corrupted), added title.rs middleware
skeleton, fixed RegisterDeviceRequest visibility.

docker-compose.yml

@@ -45,10 +45,10 @@ services:
     restart: unless-stopped
 
     ports:
-      - "${SAAS_PORT:-8080}:8080"
+      - "127.0.0.1:${SAAS_PORT:-8080}:8080"
 
     env_file:
-      - saas-env.example
+      - .env
 
     environment:
       DATABASE_URL: postgres://${POSTGRES_USER:-postgres}:${POSTGRES_PASSWORD:-your_secure_password}@postgres:5432/${POSTGRES_DB:-zclaw}