chore: add open-source community files and CI workflow

- LICENSE (MIT)
- SECURITY.md (vulnerability reporting policy)
- CONTRIBUTING.md (development setup and contribution guide)
- CI workflow (fmt, clippy, test on push/PR)
- Issue templates (bug report, feature request)
- Dependabot config (cargo + github-actions weekly)
- Cargo.toml workspace metadata (license, repository, description)

.github/workflows/ci.yml

@@ -0,0 +1,36 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  fmt:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+      - run: cargo fmt --check
+
+  clippy:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+      - run: cargo clippy -- -D warnings
+
+  test:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - run: cargo test