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.

crates/zclaw-saas/src/main.rs

@@ -40,6 +40,44 @@ async fn main() -> anyhow::Result<()> {
     let shutdown_token = CancellationToken::new();
     let state = AppState::new(db.clone(), config.clone(), dispatcher, shutdown_token.clone())?;
 
+    // Restore rate limit counts from DB so limits survive server restarts
+    {
+        let rows: Vec<(String, i64)> = sqlx::query_as(
+            "SELECT key, SUM(count) FROM rate_limit_events WHERE window_start > NOW() - interval '1 hour' GROUP BY key"
+        )
+        .fetch_all(&db)
+        .await
+        .unwrap_or_default();
+
+        let mut restored_count = 0usize;
+        for (key, count) in rows {
+            let mut entries = Vec::new();
+            // Approximate: insert count timestamps at "now" — the DashMap will
+            // expire them naturally via the retain() call in the middleware.
+            // This is intentionally approximate; exact window alignment is not
+            // required for rate limiting correctness.
+            for _ in 0..count as usize {
+                entries.push(std::time::Instant::now());
+            }
+            state.rate_limit_entries.insert(key, entries);
+            restored_count += 1;
+        }
+        info!("Restored rate limit state from DB: {} keys", restored_count);
+    }
+
+    // 迁移旧格式 TOTP secret（明文 → 加密 enc: 格式）
+    {
+        let config_for_migration = state.config.read().await;
+        if let Ok(enc_key) = config_for_migration.totp_encryption_key() {
+            drop(config_for_migration);
+            if let Err(e) = zclaw_saas::crypto::migrate_legacy_totp_secrets(&db, &enc_key).await {
+                tracing::warn!("TOTP legacy migration check failed: {}", e);
+            }
+        } else {
+            drop(config_for_migration);
+        }
+    }
+
     // 启动声明式 Scheduler（从 TOML 配置读取定时任务）
     let scheduler_config = &config.scheduler;
     zclaw_saas::scheduler::start_scheduler(scheduler_config, db.clone(), state.worker_dispatcher.clone_ref());