ci: add Gitea CI, RPM spec, license, and repo hygiene

- Add .gitea/workflows/ci.yml with fmt/clippy/test on all branches
  and SRPM build + COPR publish on version tags
- Add cortex.spec for Fedora RPM packaging
- Add GPL-3.0-or-later LICENSE file
- Add cortex.example.toml with generic hostnames; gitignore cortex.toml
- Scrub infrastructure-specific hostnames from README.md, CLAUDE.md,
  and doc comments
- Fix unused imports and clippy warnings to pass -D warnings
- Fix missing deps (bytes, reqwest, serde_json) exposed during build
- Run cargo fmt across workspace
- Update SPDX license identifier to GPL-3.0-or-later

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cortex.spec

@@ -0,0 +1,49 @@
+Name:           cortex
+Version:        0.1.0
+Release:        1%{?dist}
+Summary:        Inference gateway for multi-node mistral.rs clusters
+
+License:        GPL-3.0-or-later
+URL:            https://git.lair.cafe/helexa/cortex
+Source0:        %{name}-%{version}.tar.gz
+Source1:        %{name}-%{version}-vendor.tar.gz
+
+ExclusiveArch:  x86_64
+
+BuildRequires:  rust >= 1.85
+BuildRequires:  cargo
+BuildRequires:  gcc
+BuildRequires:  systemd-rpm-macros
+
+%description
+Cortex is a Rust reverse-proxy that sits in front of multiple mistral.rs
+inference nodes and presents a unified OpenAI and Anthropic compatible
+API surface. It handles model routing, lifecycle management, request
+translation, and metrics collection.
+
+%prep
+%autosetup
+tar xf %{SOURCE1}
+mkdir -p .cargo
+cat > .cargo/config.toml << 'EOF'
+[source.crates-io]
+replace-with = "vendored-sources"
+
+[source.vendored-sources]
+directory = "vendor"
+EOF
+
+%build
+cargo build --release -p cortex-cli
+
+%install
+install -Dm755 target/release/cortex %{buildroot}%{_bindir}/cortex
+
+%files
+%license LICENSE
+%doc README.md
+%{_bindir}/cortex
+
+%changelog
+* Mon Apr 14 2026 Rob Thijssen <grenade@rob.tn> - 0.1.0-1
+- Initial package