feat(CF-1354): Add withSentryTransaction to tool handlers

Wrap CallToolRequest handler with withSentryTransaction for
per-tool tracing. Remove broken $(vault) DSN from .env.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.env

@@ -11,7 +11,7 @@
 # - PostgreSQL integration for database error tracking
 #
 # Created: 2026-01-29
-SENTRY_DSN=$(vault get sentry.dsn.mcp-servers)
+# SENTRY_DSN provided via ~/.claude.json env (dotenv can't expand shell commands)
 SENTRY_ENVIRONMENT=production
 SENTRY_TRACE_SAMPLE_RATE=0.1
 SENTRY_PROFILE_SAMPLE_RATE=0.01

src/index.ts

@@ -19,7 +19,7 @@ const envPath = join(__dirname, '..', '.env');
 const result = dotenv.config({ path: envPath, override: true });
 
 // Initialize Sentry for error tracking
-import { initSentry } from './sentry.js';
+import { initSentry, withSentryTransaction } from './sentry.js';
 initSentry(process.env.SENTRY_ENVIRONMENT || 'production');
 
 if (result.error) {
@@ -99,6 +99,7 @@ server.setRequestHandler(ListToolsRequestSchema, async () => ({
 server.setRequestHandler(CallToolRequestSchema, async (request) => {
   const { name, arguments: args } = request.params;
 
+  return withSentryTransaction(name, async () => {
   try {
     let result: string;
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -544,6 +545,7 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
     };
   }
   });
+});
 
 // Main entry point
 async function main() {