ghp: install fork deps before building (tsdown not on PATH otherwise)

Author: ryan-williams

.github/workflows/ghp.yml

@@ -17,12 +17,16 @@ jobs:
       - uses: pnpm/action-setup@v4
         with:
           version: 10
-      - run: pnpm i --no-frozen-lockfile
-      # Slidev fork ships TypeScript source only (no `dist/` in git);
-      # build its packages so `@slidev/cli` has a runnable `dist/cli.mjs`.
-      - name: Build slidev fork
+      # Slidev fork ships TS source only (no `dist/` in git); install its own
+      # workspace deps (tsdown etc.) and build its packages so `@slidev/cli`
+      # has a runnable `dist/cli.mjs`. Must happen BEFORE the deck's install,
+      # because the deck's `pnpm-workspace.yaml` links to the fork's packages.
+      - name: Install + build slidev fork
         working-directory: ../../slidev
-        run: pnpm build
+        run: |
+          pnpm install --no-frozen-lockfile
+          pnpm build
+      - run: pnpm i --no-frozen-lockfile
       - run: pnpm build
       - uses: JamesIves/github-pages-deploy-action@v4
         with: