Fix pnpm cache: use inline export instead of workflow env block

act_runner v0.3.0 doesn't propagate workflow-level or job-level
env: blocks to job containers. Use export in run commands instead.
First run warms cache, subsequent runs will show reused packages.

.gitea/workflows/ci.yaml

@@ -10,21 +10,24 @@ concurrency:
   group: ${{ gitea.workflow }}-${{ gitea.ref }}
   cancel-in-progress: true
 
-env:
-  PNPM_STORE_DIR: /pnpm-store
-  COREPACK_HOME: /pnpm-store/.corepack
-
 jobs:
   lint-and-test:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
 
-      - run: corepack enable && corepack prepare pnpm@latest --activate
+      - name: Setup pnpm
+        run: |
+          export COREPACK_HOME=/pnpm-store/.corepack
+          corepack enable && corepack prepare pnpm@latest --activate
 
-      - run: pnpm install --frozen-lockfile
+      - name: Install dependencies
+        run: |
+          export PNPM_STORE_DIR=/pnpm-store
+          pnpm install --frozen-lockfile
 
-      - run: pnpm turbo lint test
+      - name: Lint and test
+        run: pnpm turbo lint test
 
   build:
     needs: [lint-and-test]
@@ -34,9 +37,15 @@ jobs:
         with:
           fetch-depth: 0
 
-      - run: corepack enable && corepack prepare pnpm@latest --activate
+      - name: Setup pnpm
+        run: |
+          export COREPACK_HOME=/pnpm-store/.corepack
+          corepack enable && corepack prepare pnpm@latest --activate
 
-      - run: pnpm install --frozen-lockfile
+      - name: Install dependencies
+        run: |
+          export PNPM_STORE_DIR=/pnpm-store
+          pnpm install --frozen-lockfile
 
       - name: Detect and build changed apps
         run: |