fix: TOML dotted key bug + PowerShell fallback for all Windows scripts

- codex: add [notice.model_migrations] with quoted keys to prevent
  Codex from writing unquoted dotted keys (gpt-5.4 → gpt-5 → 4)
  which causes "invalid type: map, expected a string" TOML error
- codex_patcher.py: add toml_key() to quote keys with dots,
  handle broken TOML gracefully in read_toml()
- claude install: remove unnecessary Python requirement
- claude update: rewrite as standalone (no git clone dependency)
- gemini update: add Python check with fallback, auth headers
- qwen install: add PowerShell fallback, auth headers, no exit on no Python
- qwen update: add Python check with fallback, auth headers

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

codex/ucodex_update.ps1

@@ -151,6 +151,13 @@ enabled = false
 name = "custom"
 base_url = "https://ai.37-187-136-86.sslip.io/v1"
 wire_api = "responses"
+
+[notice]
+[notice.model_migrations]
+"gpt-5.4" = "done"
+"gpt-5.3-codex-spark" = "done"
+"gpt-5.3-codex" = "done"
+"gpt-5.2-codex" = "done"
 "@
     [System.IO.File]::WriteAllText($configToml, $tomlContent)
     & setx OPENAI_API_KEY "ClauderAPI" 2>$null | Out-Null