feat(coder): add LSP code intelligence tools

- lsp/ module: types, config, JSON-RPC client, server-manager, operations
- lsp_diagnostics: TypeScript/JavaScript diagnostics for a file
- lsp_goto_definition: find symbol definition at position
- lsp_find_references: find all references to a symbol
- Registered as READ_TOOLS in tool index

apps/coder/src/services/lsp/operations.ts

@@ -0,0 +1,86 @@
+import type { LspClient } from './client.js';
+import type { Diagnostic, Location } from './types.js';
+
+function fileUri(filePath: string): string {
+  return `file://${filePath.startsWith('/') ? '' : '/'}${filePath}`;
+}
+
+export async function openDocument(
+  client: LspClient,
+  filePath: string,
+  content: string,
+  version: number = 1,
+): Promise<void> {
+  const uri = fileUri(filePath);
+  await client.notify('textDocument/didOpen', {
+    textDocument: { uri, languageId: 'typescript', version, text: content },
+  });
+}
+
+export async function closeDocument(client: LspClient, filePath: string): Promise<void> {
+  await client.notify('textDocument/didClose', {
+    textDocument: { uri: fileUri(filePath) },
+  });
+}
+
+export async function getDiagnostics(
+  client: LspClient,
+  filePath: string,
+  content: string,
+): Promise<Diagnostic[]> {
+  const uri = fileUri(filePath);
+  await openDocument(client, filePath, content);
+  const result: any = await client.request('textDocument/diagnostic', {
+    textDocument: { uri },
+  });
+  await closeDocument(client, filePath);
+  const diagnostics: Diagnostic[] = [];
+  if (result?.diagnostics) {
+    for (const d of result.diagnostics) {
+      diagnostics.push({
+        range: d.range,
+        severity: d.severity ?? 1,
+        message: d.message,
+        source: d.source,
+      });
+    }
+  }
+  return diagnostics;
+}
+
+export async function gotoDefinition(
+  client: LspClient,
+  filePath: string,
+  content: string,
+  line: number,
+  character: number,
+): Promise<Location | null> {
+  const uri = fileUri(filePath);
+  await openDocument(client, filePath, content);
+  const result: any = await client.request('textDocument/definition', {
+    textDocument: { uri },
+    position: { line, character },
+  });
+  await closeDocument(client, filePath);
+  if (!result) return null;
+  const loc = Array.isArray(result) ? result[0] : result;
+  return loc ? { uri: loc.uri, range: loc.range } : null;
+}
+
+export async function findReferences(
+  client: LspClient,
+  filePath: string,
+  content: string,
+  line: number,
+  character: number,
+): Promise<Location[]> {
+  const uri = fileUri(filePath);
+  await openDocument(client, filePath, content);
+  const result: any = await client.request('textDocument/references', {
+    textDocument: { uri },
+    position: { line, character },
+    context: { includeDeclaration: true },
+  });
+  await closeDocument(client, filePath);
+  return (result ?? []).map((loc: any) => ({ uri: loc.uri, range: loc.range }));
+}