fix(mcp): unbreak the MCP server deploy by excluding tests from the prod build

The last three pushes to master failed `deploy-mcp.yml` at the Docker build:

    src/branding.test.ts(1,38): error TS2307: Cannot find module 'vitest'
    src/tools/flashcards.test.ts(104,91): error TS7006: Parameter 'rating'
      implicitly has an 'any' type.

`mcp-server` declares a vitest config but not the dependency — locally the
import resolves upward into the repo root's node_modules. The image copies
only `mcp-server/`, so there is no root to walk up to and the type check
fails. Test files also have no business in `dist`, so exclude them from the
build rather than shipping vitest into the production image.

Verified with a local `docker build` of mcp-server/Dockerfile: type check
passes, 18 widgets built. `npx vitest run` in mcp-server still passes 66/66.

Author: guillermoscript

mcp-server/tsconfig.json

@@ -20,5 +20,8 @@
     }
   },
   "include": ["index.ts", "src/**/*", "resources/**/*", "server.ts", ".mcp-use/**/*.d.ts"],
-  "exclude": ["node_modules", "dist"]
+  // Test files are excluded from the build: `vitest` resolves from the repo
+  // root's node_modules here, but the Docker image copies only mcp-server/,
+  // so compiling them fails the production build with TS2307.
+  "exclude": ["node_modules", "dist", "**/*.test.ts", "**/*.test.tsx"]
 }