feat(aiturk): one-click sign-in for AITURK IDE (1.0.0-beta.14)

The onboarding and provider settings get a Sign in button: the IDE shows a
short code, opens the turkservis.online approval page, and after approval
saves the TurkServis provider itself and hands a separate member key to the
AITURK CLI over stdin (aiturk login --key-stdin --keep-other-account).
Keys never reach the renderer, logs, process arguments or URLs. Pasting an
API key remains as the fallback.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B8ppceaR5s6cvMnm7uGRnf

package-lock.json

@@ -65,7 +65,7 @@
     },
     "apps/desktop": {
       "name": "aiturk-ide",
-      "version": "1.0.0-beta.13",
+      "version": "1.0.0-beta.14",
       "license": "MIT",
       "dependencies": {
         "@assistant-ui/core": "0.2.23",