perf,feat(events),hardening: second review pass

Fleet overview N+1:
- InstanceResourceService gains a 30s TTL cache with single-flight
  coalescing; the overview no longer fires six live upstream requests per
  device on every render (plus the re-login storm), while the per-device
  detail route probes live via force:true

Event journal becomes live:
- job terminal transitions (manual executions and the interrupted sweep)
  now append to the journal, so /api/v1/events SSE feeds the frontend's
  invalidation controller that was built but never received events
- journal pruning moves off the append hot path (was an unindexable
  full-table json_extract scan per insert) onto the retention timer

Console auth hardening:
- scrypt upgraded from N=16384 to N=2^16 (OWASP interactive guidance);
  a new password_kdf column records the derivation per row and legacy
  hashes rehash transparently on the next successful login without
  invalidating sessions (migration 18)

Legacy stack:
- instance URL validation blocks IPv4-compatible IPv6 after WHATWG
  canonicalization (::a9fe:a9fe metadata, ::7f00:1 loopback slipped past)
- status polls cool down auto-login for 60s after a failed attempt so a
  stale saved password cannot hammer the device into an account lockout

Build hygiene:
- web bundle splits app (410kB) from vendor (212kB) so framework code
  stays cacheable across releases; stale root package-lock.json removed
  (pnpm is the only lockfile)

README.md

@@ -80,10 +80,12 @@ sh /tmp/multi-simadmin-install.sh uninstall
 
 ```bash
 cp config.example.json config.json
-npm install
-npm start
+corepack pnpm install
+corepack pnpm start
 ```
 
+> 仓库统一使用 pnpm（`pnpm-lock.yaml`）作为唯一 lockfile；陈旧的 `package-lock.json` 已移除。
+
 ## 配置
 
 编辑 `config.json`：