fix: DB backup on schema change, MCP child cleanup, codex models, usage providers OOM

- Backup DB only on real SCHEMA_VERSION change, not every app version bump
- Kill idle MCP stdio bridge children to prevent orphan process leaks
- Add getDistinctProviders to avoid loading every row JSON blob (OOM fix)
- Update codex model list (gpt-5.6 sol/terra/luna, drop 5.3 codex variants)
- Reorder Claude default models (fable first)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/shared/services/initializeApp.js

@@ -16,6 +16,7 @@ import {
 import { getMitmStatus, startMitm, loadEncryptedPassword, initDbHooks, restoreToolDNS, removeAllDNSEntriesSync } from "@/mitm/manager";
 import { startQuotaAutoPing } from "@/shared/services/quotaAutoPing";
 import { syncToJson as syncMitmAliasCache } from "@/lib/mitmAliasCache";
+import { killAllBridges } from "@/lib/mcp/stdioSseBridge";
 
 // Inject correct paths and DB hooks into manager.js (CJS) from ESM context
 (function bootstrapMitm() {
@@ -56,6 +57,7 @@ export async function initializeApp() {
     if (!g.signalHandlersRegistered) {
       const cleanup = () => {
         try { removeAllDNSEntriesSync(); } catch { /* best effort */ }
+        try { killAllBridges(); } catch { /* best effort */ }
         killCloudflared();
         process.exit();
       };