fix: swap bun install for npm ci to fix integrity check failures

Known Bun bug (oven-sh/bun#1590, #26879, #18864) causes
IntegrityCheckFailed during tarball extraction in Docker/CI.
This is a 3+ year old issue with no fix in sight.

Changes:
- Generate package-lock.json via npm install --package-lock-only
- Dockerfile: add nodejs npm to all stages, replace bun install
  with npm ci --legacy-peer-deps (peer dep conflict exists for
  eslint@8 with eslint-config-next@16)
- Keep bun as runtime (bun test, bun run build, bun run start)
- pr.yml: npm ci, npx prisma generate, npx playwright
- release.yml: node scripts, npm test
- build-ci-images.yml: add package-lock.json trigger path

.gitea/workflows/pr.yml

@@ -23,13 +23,13 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install dependencies
-        run: bun install --retry 3
+        run: npm ci --legacy-peer-deps
 
       - name: Generate Prisma client
-        run: bun x prisma generate
+        run: npx prisma generate
 
       - name: Run unit tests
-        run: bun test src/__tests__/unit/ src/__tests__/*.test.tsx src/__tests__/auth-simple.test.ts
+        run: npm test
 
   build-and-deploy-ci:
     runs-on: ubuntu-latest
@@ -45,10 +45,10 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install dependencies
-        run: bun install --retry 3
+        run: npm ci --legacy-peer-deps
 
       - name: Generate Prisma client
-        run: bun x prisma generate
+        run: npx prisma generate
         env:
           DATABASE_URL: postgresql://user:pass@localhost:5432/dummy
 
@@ -93,7 +93,7 @@ jobs:
           exit 1
 
       - name: Run acceptance tests
-        run: DATABASE_URL="${{ secrets.CI_DATABASE_URL }}" bun test:acceptance
+        run: DATABASE_URL="${{ secrets.CI_DATABASE_URL }}" npx playwright test e2e/
         env:
           CI: true