fix(mcp-server): review fixes for the shell's build

tsc -p shell checked nothing: the inherited exclude dropped every shell
file; the shell's tsconfig now excludes node_modules only. Tailwind scans
app-toaster.tsx too, so the sync notices look like the web app's toasts.
The bundle keeps its dependencies' license comments (esbuild appends them
at the end). postcss, which build-shell.mjs loads from the root, is a
declared devDependency.

packages/mcp-server/scripts/build-shell.mjs

@@ -35,7 +35,6 @@ const result = await build({
     target: "es2022",
     platform: "browser",
     jsx: "automatic",
-    legalComments: "none",
     metafile: true,
     absWorkingDir: root,
     alias: {