Refactor LSP tools and add hover functionality

- Split diagnostics tool into separate lsp-diagnostics.ts file
- Add new lsp-hover.ts tool for LSP hover information
- Update tool exports and session integration
- Remove old diagnostics.ts file

🤖 Generated with opencode
Co-Authored-By: opencode <noreply@opencode.ai>

js/bun.lock

@@ -11,6 +11,7 @@
         "ai": "^5.0.0-alpha.4",
         "cac": "^6.7.14",
         "clipanion": "^4.0.0-rc.4",
+        "diff": "^8.0.2",
         "hono": "^4.7.10",
         "hono-openapi": "^0.4.8",
         "jsdom": "^26.1.0",
@@ -159,6 +160,8 @@
 
     "decimal.js": ["decimal.js@10.5.0", "", {}, "sha512-8vDa8Qxvr/+d94hSh5P3IJwI5t8/c0KsMp+g8bNw9cY2icONa5aPfvKeieW1WlG0WQYwwhJ7mjui2xtiePQSXw=="],
 
+    "diff": ["diff@8.0.2", "", {}, "sha512-sSuxWU5j5SR9QQji/o2qMvqRNYRDOcBTgsJ/DeCf4iSN4gW+gNMXM7wFIP+fdXZxoNiAnHUTGjCr+TSWXdRDKg=="],
+
     "duplexify": ["duplexify@4.1.3", "", { "dependencies": { "end-of-stream": "^1.4.1", "inherits": "^2.0.3", "readable-stream": "^3.1.1", "stream-shift": "^1.0.2" } }, "sha512-M3BmBhwJRZsSx38lZyhE53Csddgzl5R7xGJNk7CVddZD6CcmwMCH8J+7AprIrQKH7TonKxaCjcv27Qmf+sQ+oA=="],
 
     "emoji-regex": ["emoji-regex@10.4.0", "", {}, "sha512-EC+0oUMY1Rqm4O6LLrgjtYDvcVYTy7chDnM4Q7030tP4Kwj3u/pR6gP9ygnp2CJMK5Gq+9Q2oqmrFJAz01DXjw=="],