refactor(cli): streamline multiline input keyboard handling and remove unused clamp helper. Standardize deletion/navigation shortcuts across macOS/Windows to improve reliability and consistency.

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Co-Authored-By: Codebuff <noreply@codebuff.com>

Author: brandonkachen

cli/.gitignore

@@ -2,3 +2,4 @@ node_modules
 dist
 *.log
 .DS_Store
+debug/

cli/package.json

@@ -25,6 +25,7 @@
     "bun": ">=1.2.11"
   },
   "dependencies": {
+    "@codebuff/sdk": "workspace:*",
     "@opentui/react": "^0.1.25",
     "react": "^19.0.0",
     "remark-parse": "^11.0.0",