feat: add playable card system and Coatcheck suite

.github/README.md

@@ -0,0 +1,5 @@
+# GitHub automation
+
+Repository automation is kept under [workflows](workflows/README.md).
+
+[Back to the repository root](../README.md).

.github/workflows/README.md

@@ -0,0 +1,7 @@
+# Workflows
+
+`ci.yml` runs the workspace’s formatting, Clippy, Rust tests, JavaScript syntax
+gate, and all manifest-driven/custom Coatcheck browser checks in Chromium.
+
+- [GitHub automation](../README.md)
+- [Repository root](../../README.md)

.github/workflows/ci.yml

@@ -21,3 +21,18 @@ jobs:
       - run: cargo clippy --workspace --all-targets --all-features -- -D warnings
       - run: cargo test --workspace --all-features
       - run: node --check crates/coldfront-ui/src/auth.js
+
+  coatcheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@1.97.1
+      - uses: Swatinem/rust-cache@v2
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: 1.3.1
+      - run: cargo install topcoat-cli --version 0.4.0 --locked --root .tools
+      - run: cargo install coatcheck --version 0.2.0 --locked --root .tools
+      - run: bun install --frozen-lockfile
+      - run: bunx playwright install --with-deps chromium
+      - run: ./scripts/test-coatcheck

.gitignore

@@ -1,6 +1,11 @@
 /target
 /dist
 /.tools
+/node_modules
+/.coatcheck
+/playwright-report
+/test-results
+/tools/tophat-testing
 .DS_Store
 .env
 .env.*