chore: fix monorepo build pipeline and migrate shared to built package

- Root package.json: add workspace scripts (dev, build, test, test:cov, test:e2e)
  that delegate to actual scripts in shared/server/client workspaces
- shared: add tsup build step (CJS + ESM dual output, .d.ts); consumers now import
  from the built dist instead of raw TS source via path aliases
- server: replace tsc-alias with tsconfig-paths (tsc-alias mangled node_modules
  paths); fix MCP SDK path aliases to point to root node_modules (../node_modules)
- server/scripts/dev.mjs: delay node --watch until tsc -w signals first-pass done,
  eliminating the spurious restart on every dev startup
- client/vite.config.js + vitest.config.ts: remove @trek/shared path alias (no longer
  needed now that shared is a proper package)
- Consolidate package-lock.json at the workspace root; drop per-workspace lock files

server/vitest.config.ts

@@ -38,9 +38,6 @@ export default defineConfig({
   },
   resolve: {
     alias: {
-      // @trek/shared — Zod contract package (tests resolve it to TS source,
-      // mirroring the tsconfig `paths` the tsx runtime uses).
-      '@trek/shared': new URL('../shared/src/index.ts', import.meta.url).pathname,
       '@modelcontextprotocol/sdk/server/mcp': new URL(
           './node_modules/@modelcontextprotocol/sdk/dist/cjs/server/mcp.js',
           import.meta.url
@@ -58,12 +55,5 @@ export default defineConfig({
           import.meta.url
       ).pathname,
     },
-    // The server build emits @trek/shared next to its source (shared/src/*.js,
-    // needed by the prod dist via tsc-alias). Vite's default extension order
-    // prefers .js over .ts, so after a build the tests would load that compiled
-    // CJS instead of the source — and its `require('zod')` is unresolvable from
-    // the shared/ dir on CI (only server deps are installed there). Resolve .ts
-    // first so tests always run the source, whose zod import resolves via Vite.
-    extensions: ['.ts', '.mts', '.mjs', '.js', '.cts', '.cjs', '.tsx', '.jsx', '.json'],
   },
 });