migrate from yarn 1 to pnpm

- switch root package manager to pnpm 10.33.4 via packageManager field
- add .npmrc with node-linker=hoisted for RN/Expo compatibility
- convert yarn resolutions to pnpm.overrides; pin psl@1.9.0 and @types/psl@1.1.1
  to keep types resolving under exports-aware resolution
- pin react-compiler-runtime and babel-plugin-react-compiler to real rc.3 (the
  deprecated "Wrong version name was published" tag would otherwise resolve)
- add pnpm.onlyBuiltDependencies allowlist for @sentry/cli, core-js-pure,
  esbuild, unrs-resolver
- regenerate pnpm-lock.yaml; delete yarn.lock; drop postinstall-postinstall
- update all workflows, Dockerfile, Dockerfile.embedr (root-level), Makefile,
  conductor.json; bskyembed/bskylink/bskyogcard/dev-env stay on yarn
- update docs (CLAUDE.md, docs/build.md, docs/testing.md, docs/localization.md,
  bskyweb/README.md, scripts/push-notification/README.md, BlueskyClip/README.md)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/lint.yml

@@ -41,46 +41,48 @@ jobs:
           v=$(grep -oE '"node":[[:space:]]*"[0-9]+\.[0-9]+\.[0-9]+"' eas.json | grep -oE '[0-9]+\.[0-9]+\.[0-9]+' | sort -u)
           check "eas.json" "$v"
           exit $rc
+      - uses: pnpm/action-setup@v4
       - name: Install node
         uses: actions/setup-node@v6
         with:
           node-version-file: .nvmrc
-          cache: yarn
-      - name: Yarn install
+          cache: pnpm
+      - name: pnpm install
         uses: Wandalen/wretry.action@master
         with:
-          command: yarn --frozen-lockfile
+          command: pnpm install --frozen-lockfile
           attempt_limit: 3
           attempt_delay: 2000
       - name: Lint check
-        run: yarn lint
+        run: pnpm lint
       - name: Lint lockfile
-        run: yarn lockfile-lint
+        run: pnpm lockfile-lint
       - name: Prettier check
-        run: yarn prettier --check .
+        run: pnpm prettier --check .
       - name: Check & compile i18n
-        run: yarn intl:build
+        run: pnpm intl:build
       - name: Type check
-        run: yarn typecheck
+        run: pnpm typecheck
   testing:
     name: Run tests
     runs-on: ubuntu-latest
     steps:
       - name: Check out Git repository
         uses: actions/checkout@v4
+      - uses: pnpm/action-setup@v4
       - name: Install node
         uses: actions/setup-node@v6
         with:
           node-version-file: .nvmrc
-          cache: yarn
-      - name: Yarn install
+          cache: pnpm
+      - name: pnpm install
         uses: Wandalen/wretry.action@master
         with:
-          command: yarn --frozen-lockfile
+          command: pnpm install --frozen-lockfile
           attempt_limit: 3
           attempt_delay: 2000
       - name: Check & compile i18n
-        run: yarn intl:build
+        run: pnpm intl:build
       - name: Run tests
         run: |
-          NODE_ENV=test yarn test --forceExit
+          NODE_ENV=test pnpm test --forceExit