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+# Phase 1 — minimum-viable CI per RESEARCH Open Question #4 + CONTEXT user pushback
+# against ceremonial workflows (.planning/phases/01-foundations-and-doctrine/01-CONTEXT.md).
+#
+# On every push to main and every pull request:
+#   - npm ci (lockfile-strict install — refuses on package.json drift)
+#   - npm run ci (lint + test + validate-assets + build, defined in package.json)
+#
+# This single job satisfies PIPE-06: Vitest tests run on every CI build.
+# Phase 2+ economy tests flow through the same `npm run ci` chain — no workflow change
+# is needed when more tests are added.
+#
+# Deliberately omitted (per CONTEXT user pushback against ceremony):
+#   - OS matrix (Linux only is fine; PIPE-04 visual regression testing is Phase 8)
+#   - Node-version matrix (one supported version is enough for solo-dev)
+#   - Test reporters / Codecov uploads (no coverage requirement in Phase 1)
+#   - Release automation (no releases until Phase 2 ships Season 1)
+#   - Notification integrations (the project owner reads GitHub directly)
+
+name: ci
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  ci:
+    name: lint + test + validate-assets + build
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node 22
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          # Per RESEARCH CI Pitfall A: cache ~/.npm based on package-lock.json,
+          # NEVER cache node_modules/ directly (transitive deps go stale).
+          cache: 'npm'
+
+      - name: Install dependencies (lockfile-strict)
+        run: npm ci
+
+      - name: Run CI suite
+        run: npm run ci