feat(codex-bridge): hide 9Router combos in Codex, drop the config backup (beta.22)

Combos that come from 9Router, directly or through the gateway's 9router
provider, are no longer added to Codex's model list; the gateway's own combos
keep their plain names. The IDE no longer leaves a config.toml backup behind:
turning the setting off already restores the file byte for byte.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HRDGW1LiKcDUZYUdKBoWYW

apps/desktop/electron/codex-link.ts

@@ -23,7 +23,6 @@ import path from 'node:path'
 import {
   addCodexLinkLine,
   CODEX_BRIDGE_VERSION,
-  CODEX_LINK_BACKUP_SUFFIX,
   CODEX_LINK_LAUNCHER_NAME,
   CODEX_LINK_REFRESH_URL,
   CODEX_LINK_RUN_KEY,
@@ -67,8 +66,6 @@ export interface CodexLinkDeps {
   readText: (file: string) => null | string
   /** tmp + rename; creates the parent folder. */
   writeTextAtomic: (file: string, text: string) => void
-  /** Copy `source` to `target` unless `target` already exists. */
-  backupOnce: (source: string, target: string) => void
   /** Start the bridge detached and hidden; it must outlive the IDE. */
   spawnBridge: (command: string, args: string[], env: Record<string, string>) => void
   /** Parsed JSON body, or null when nothing answered within `budgetMs`. */
@@ -334,7 +331,6 @@ export function createCodexLink(deps: CodexLinkDeps): CodexLink {
 
     if (edit.changed) {
       try {
-        deps.backupOnce(paths.codexConfig, `${paths.codexConfig}${CODEX_LINK_BACKUP_SUFFIX}`)
         deps.writeTextAtomic(paths.codexConfig, edit.text)
       } catch (error) {
         fail('config-write-failed', error)
@@ -472,11 +468,6 @@ export function createNodeCodexLinkDeps(paths: CodexLinkPaths, log: (message: st
     exists: file => fs.existsSync(file),
     readText: readTextLossless,
     writeTextAtomic,
-    backupOnce: (source, target) => {
-      if (!fs.existsSync(target)) {
-        fs.copyFileSync(source, target, fs.constants.COPYFILE_EXCL)
-      }
-    },
     spawnBridge: (command, args, env) => {
       fs.mkdirSync(paths.bridgeHome, { recursive: true })