fix(think-mode): remove overly broad Korean keyword

Remove '고민' from MULTILINGUAL_KEYWORDS as it triggers false
positives in everyday Korean speech. The keyword '생각' (thinking)
remains for intentional think-mode activation.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/think-mode/detector.ts

@@ -1,7 +1,7 @@
 const ENGLISH_PATTERNS = [/\bultrathink\b/i, /\bthink\b/i]
 
 const MULTILINGUAL_KEYWORDS = [
-  "생각", "고민", "검토", "제대로",
+  "생각", "검토", "제대로",
   "思考", "考虑", "考慮",
   "思考", "考え", "熟考",
   "सोच", "विचार",