add CI/crates.io/license badges, cargo-audit in CI

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -24,3 +24,5 @@ jobs:
         run: cargo clippy -- -D warnings
       - name: test
         run: cargo test
+      - name: audit
+        run: cargo install cargo-audit && cargo audit

README.md

@@ -1,5 +1,9 @@
 # Numa
 
+[![CI](https://github.com/razvandimescu/numa/actions/workflows/ci.yml/badge.svg)](https://github.com/razvandimescu/numa/actions)
+[![crates.io](https://img.shields.io/crates/v/numa.svg)](https://crates.io/crates/numa)
+[![License: MIT](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
+
 **DNS you own. Everywhere you go.**
 
 A portable DNS resolver in a single binary. Block ads on any network, name your local services (`frontend.numa`), and override any hostname with auto-revert — all from your laptop, no cloud account or Raspberry Pi required.