fix(ci): build shared before tests; fix vitest MCP SDK alias paths

vitest.config.ts aliases pointed at ./node_modules/ (server-local) but
packages are hoisted to the root node_modules/ in the npm workspace —
changed to ../node_modules/.

CI jobs now install and build shared before running server/client tests
so that @trek/shared's dist/ exists when vitest resolves the package.

.github/workflows/test.yml

@@ -49,14 +49,17 @@ jobs:
           cache-dependency-path: package-lock.json
 
       - name: Install dependencies
-        run: npm ci --workspace server
+        run: npm ci --workspace shared && npm ci --workspace server
 
-      - name: Build (tsc + tsc-alias -> dist)
+      - name: Build shared
+        run: npm run build --workspace=shared
+
+      - name: Build server (tsc -> dist)
         run: cd server && npm run build
 
       - name: Typecheck (informational)
-        # Legacy code still has pre-existing type errors; this surfaces them
-        # without blocking the migration. Ratchet to blocking once cleaned up.
+        # Pre-existing type errors in the NestJS rewrite; surfaces them without
+        # blocking CI. Ratchet to blocking once the legacy code is cleaned up.
         continue-on-error: true
         run: cd server && npm run typecheck
 
@@ -85,7 +88,10 @@ jobs:
           cache-dependency-path: package-lock.json
 
       - name: Install dependencies
-        run: npm ci --workspace client
+        run: npm ci --workspace shared && npm ci --workspace client
+
+      - name: Build shared
+        run: npm run build --workspace=shared
 
       - name: Run tests
         run: cd client && npm run test:coverage