diff --git a/.github/workflows/fork-patches.yml b/.github/workflows/fork-patches.yml
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+name: Fork Patches CI
+
+# CI for the fork-patches integration branch.
+#
+# Why this exists (FLO-520): pr.yml only triggers on pull_request -> master, and a
+# fork-patches -> master PR spans ~300 commits and carries pnpm-lock.yaml changes, so the
+# pr.yml `policy` job's manual-lockfile-edit guard fails and every job that needs:[policy]
+# (including the DB-backed serialized server suite) is skipped. As a result, patches landing
+# on fork-patches got no CI at all. This workflow gives fork-patches its own minimal,
+# self-contained lane: full typecheck + the embedded-postgres serialized server tests, on
+# x86 GitHub-hosted runners (the maintainer works on ARM, so these can't be run locally).
+#
+# It deliberately does NOT re-run the pr.yml policy/lockfile-guard machinery: the committed
+# pnpm-lock.yaml is authoritative on fork-patches, and `--frozen-lockfile` here doubles as a
+# lockfile-consistency check.
+
+on:
+  push:
+    branches:
+      - fork-patches
+  pull_request:
+    branches:
+      - fork-patches
+
+concurrency:
+  group: fork-patches-ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  typecheck:
+    name: Typecheck
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v6
+        with:
+          version: 9.15.4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Typecheck
+        run: pnpm run typecheck
+
+  serialized_server:
+    name: Serialized server tests (${{ matrix.shard_label }})
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - shard_index: 0
+            shard_count: 4
+            shard_label: 1/4
+          - shard_index: 1
+            shard_count: 4
+            shard_label: 2/4
+          - shard_index: 2
+            shard_count: 4
+            shard_label: 3/4
+          - shard_index: 3
+            shard_count: 4
+            shard_label: 4/4
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v6
+        with:
+          version: 9.15.4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run serialized server test shard
+        run: pnpm test:run:serialized -- --shard-index ${{ matrix.shard_index }} --shard-count ${{ matrix.shard_count }}