[vernonstinebaker]

Adds the contribution flow (commit gates: zig build test, e2e suite, zig fmt; CI matrix expectations; regression-test mandate; OpenAPI sync obligation for REST changes). Complements the existing AGENTS.md, which stays the engineering protocol. Docs-only.

[DonPrus]

The contribution guide usefully complements the existing AGENTS.md rather than introducing a second engineering protocol. I checked its commands against build.zig, the E2E script and CI, checked the linked file, and verified the OpenAPI routes share the embedded src/openapi.json contract. The documentation-only change merges cleanly with current main.

One non-blocking correction: it would be great to replace “4-target CI matrix” with “unit tests on Linux, macOS and Windows, plus Linux aarch64/riscv64 cross-compilation.” The actual workflow has three test jobs; the two additional Linux architectures are build-only checks, and riscv64 is currently omitted from this list. This makes the contribution requirements match what CI really verifies.

For context, main's current configuration-test compilation failure is independently addressed and validated in #13; it is not introduced by this documentation PR. No blocking findings here.

[vernonstinebaker]

Addressed in 0a769bf — item 4 now reads "unit tests on Linux, macOS and Windows, plus Linux aarch64/riscv64 cross-compilation", i.e. your wording.

Verified against .github/workflows/ci.yml first: the matrix has exactly 3 entries (ubuntu-latest, macos-latest, windows-latest), each running Run unit tests + Run E2E tests; and Cross-compile linux-aarch64 / Cross-compile linux-riscv64 are both zig build only with if: runner.os == 'Linux' — build-only, no test run. So the old "4-target" line both promoted a build-only arch to a test target and omitted riscv64.

Docs-only, +15/-0 on one new file. CI running; approval retained.