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

client/vite.config.js

@@ -1,7 +1,6 @@
 import { defineConfig } from 'vite'
 import react from '@vitejs/plugin-react'
 import { VitePWA } from 'vite-plugin-pwa'
-import { fileURLToPath } from 'node:url'
 
 export default defineConfig({
   plugins: [
@@ -89,15 +88,6 @@ export default defineConfig({
       },
     }),
   ],
-  resolve: {
-    alias: {
-      // @trek/shared — Zod contract package (dev: resolved to TS source).
-      '@trek/shared': fileURLToPath(new URL('../shared/src/index.ts', import.meta.url)),
-    },
-    // @trek/shared imports zod from its own source; it lives outside this root,
-    // so pin zod to the client's copy (one instance, resolvable from anywhere).
-    dedupe: ['zod'],
-  },
   build: {
     sourcemap: false,
     modulePreload: { polyfill: true },