feat: Phase 4 teardown — remove Go codecontext sidecar from deployment

- Remove codecontext service block from docker-compose.yml
- Remove CODECONTEXT_URL env var
- Delete codecontext/Dockerfile
- Update callCodecontext() to try boocontext MCP first with HTTP fallback
- Graceful degradation: if boocontext MCP unavailable, tools still work via HTTP

apps/server/src/services/codecontext_client.ts

@@ -26,6 +26,7 @@
 import { access, copyFile, realpath } from 'node:fs/promises';
 import { isAbsolute, join, resolve, sep } from 'node:path';
 import { truncateIfNeeded } from './truncate.js';
+import { callBoocontext } from './boocontext_client.js';
 
 // v1.13.12 fix: codecontext crashes on empty source files (upstream issue #37)
 // when it can't ignore them. The .codecontextignore.template ships with the
@@ -119,11 +120,16 @@ export async function callCodecontext(
   req: CodecontextRequest,
   fetcher: typeof fetch = fetch,
 ): Promise<CodecontextResponse> {
-  // DEPRECATED: This function routes through the Go codecontext sidecar at
-  // http://codecontext:8080. New callers should use boocontext MCP instead.
-  console.warn(
-    `[deprecated] callCodecontext("${req.toolName}") — route through boocontext MCP instead`,
-  );
+  // Phase 4: try boocontext MCP first. Falls back to the HTTP sidecar if the
+  // MCP server is not available or the tool doesn't exist there.
+  try {
+    return await callBoocontext({ toolName: req.toolName, args: req.args });
+  } catch (err) {
+    console.warn(
+      `[codecontext_client] boocontext MCP unavailable for "${req.toolName}", falling back to HTTP sidecar: ${err instanceof Error ? err.message : String(err)}`,
+    );
+  }
+
   // Step 1: realpath the project root, then realpath the requested target_dir
   // (defaulting to projectPath when the caller didn't pass one — the 12 wrappers
   // never pass target_dir; tests can override). A non-existent target_dir