feat(lsp): add directory support to lsp_diagnostics via extension param

- Add isDirectoryPath helper to lsp-client-wrapper.ts
- Create directory-diagnostics.ts with aggregateDiagnosticsForDirectory
- Update diagnostics-tool.ts with extension parameter for directory paths
- Update Atlas agent prompts to use extension param for directory diagnostics
- Add unit tests for isDirectoryPath and aggregateDiagnosticsForDirectory

Fixes #2362

src/tools/lsp/constants.ts

@@ -1,6 +1,7 @@
 export const DEFAULT_MAX_REFERENCES = 200
 export const DEFAULT_MAX_SYMBOLS = 200
 export const DEFAULT_MAX_DIAGNOSTICS = 200
+export const DEFAULT_MAX_DIRECTORY_FILES = 50
 
 export { SYMBOL_KIND_MAP, SEVERITY_MAP, EXT_TO_LANG } from "./language-mappings"
 export { BUILTIN_SERVERS, LSP_INSTALL_HINTS } from "./server-definitions"