refactor: codebase audit cleanup — dead code, dedup, module splits

Multi-agent audit + aggressive cleanup across server/web/coder/booterm,
delivered behind a DEFER discipline so none of the in-flight files were
touched. Removes dead code/deps/columns, dedups server + coder helpers,
and splits the oversized modules (tools.ts, opencode-server.ts,
sentinel-summaries, turn.ts, TerminalPane.tsx) behind stable contracts.
Adds 78 parity/unit tests (server 587, coder 323); fixes two latent bugs
(ChatPane queue keys, FileViewerOverlay blank-line parity).

Intended tag: v2.7.12-audit-cleanup.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/services/tools/codecontext/get_codebase_overview.ts

@@ -1,10 +1,5 @@
-// v1.12 Track B.2: codecontext wrapper — get_codebase_overview.
-// Pattern mirrors services/web_search.ts: pure executor + ToolDef wrapper.
-// target_dir is supplied by callCodecontext from the resolved project root.
-
 import { z } from 'zod';
-import type { ToolDef } from '../../tools.js';
-import { callCodecontext, type CodecontextResponse } from '../../codecontext_client.js';
+import { makeCodecontextTool } from './factory.js';
 
 export const GetCodebaseOverviewInput = z.object({
   include_stats: z.boolean().optional(),
@@ -17,43 +12,22 @@ const DESCRIPTION =
   'Tree-sitter coverage: full for JS/Python/Java/Go/Rust/C++. TypeScript symbols are approximate (uses JS grammar). ' +
   'PHP and SQL are not supported — fall back to view_file/grep for those.';
 
-export async function executeGetCodebaseOverview(
-  input: GetCodebaseOverviewInputT,
-  projectPath: string,
-  fetcher: typeof fetch = fetch,
-): Promise<CodecontextResponse> {
-  return callCodecontext(
-    {
-      toolName: 'get_codebase_overview',
-      args: { include_stats: input.include_stats ?? true },
-      projectPath,
-    },
-    fetcher,
-  );
-}
-
-export const getCodebaseOverview: ToolDef<GetCodebaseOverviewInputT> = {
-  name: 'get_codebase_overview',
-  description: DESCRIPTION,
-  inputSchema: GetCodebaseOverviewInput,
-  jsonSchema: {
-    type: 'function',
-    function: {
-      name: 'get_codebase_overview',
-      description: DESCRIPTION,
-      parameters: {
-        type: 'object',
-        properties: {
-          include_stats: {
-            type: 'boolean',
-            description: 'Include file count, symbol count, language stats. Defaults to true.',
-          },
+const { toolDef: getCodebaseOverview, execute: executeGetCodebaseOverview } =
+  makeCodecontextTool<GetCodebaseOverviewInputT>({
+    name: 'get_codebase_overview',
+    schema: GetCodebaseOverviewInput,
+    description: DESCRIPTION,
+    jsonParameters: {
+      type: 'object',
+      properties: {
+        include_stats: {
+          type: 'boolean',
+          description: 'Include file count, symbol count, language stats. Defaults to true.',
         },
-        additionalProperties: false,
       },
+      additionalProperties: false,
     },
-  },
-  async execute(input, projectRoot) {
-    return await executeGetCodebaseOverview(input, projectRoot);
-  },
-};
+    mapArgs: (input) => ({ include_stats: input.include_stats ?? true }),
+  });
+
+export { getCodebaseOverview, executeGetCodebaseOverview };