fix: stabilize TypeScript LSP startup

Seed new TypeScript LSP profiles with --stdio, validate that shared profiles keep the required flag, auto-add it for existing profiles in the sidecar runtime, and include recent stderr when a language server dies before completing a request. Add shared and sidecar regression coverage.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/App.tsx

@@ -72,7 +72,7 @@ function createDraftLspProfile(): LspProfileDefinition {
     id: createId('lsp'),
     name: 'New LSP Profile',
     command: '',
-    args: [],
+    args: ['--stdio'],
     languageId: 'typescript',
     fileExtensions: ['.ts', '.tsx'],
     createdAt: timestamp,