docs: add AGENTS.md with repo invariants for coding agents

[duyet]

Closes #25 (Plan 010).

Why

Most changes to this repo are written by coding agents, but there was no AGENTS.md. Sessions re-derived the 0.1.x lock, the release-please no-auto-merge rule, the size budget, and key redaction from README and workflows, and sometimes got them wrong.

Scope

• Adds AGENTS.md at the repo root (34 lines).
• Commands, invariants, conventions, and gotchas. Each claim is checked against README.md, release-please-config.json, tests/release_lock.rs, Cargo.toml, and src/config.rs.

Out of scope: README edits, CONTRIBUTING, any code.

Blast radius

Docs only. Agents that read AGENTS.md get the house rules without scraping workflows. Humans who ignore the file are unchanged.

Verification

• AGENTS.md exists, 34 lines (under 100).
• grep always-bump-patch release-please-config.json matches.
• cargo test --locked --test release_lock — 7 passed.
• cargo fmt --check — exit 0.
• No CLAUDE.md. Only AGENTS.md added.

Checklist

• Version stays on 0.1.x (do not introduce 0.2 / 1.0)
• Do not auto-merge release-please PRs

  

[github-actions]

anyr size and startup

Startup is wall time for a cold anyr --version / anyr --help (median of 21 runs). Size is the stripped release binary, or the .wasm for the browser demo.

Size budget: anyr-linux-x86_64 must stay ≤ 4.0 MiB (4194304 bytes) stripped.

Asset	Kind	Size	--version median	--help median
anyr-darwin-arm64	native	2.8 MiB	6.25 ms	6.15 ms
anyr-darwin-x86_64	native	3.0 MiB	45.4 ms	38.2 ms
anyr-linux-arm64	native	2.8 MiB	0.79 ms	0.8 ms
anyr-linux-x86_64	native	3.1 MiB	0.81 ms	0.8 ms
anyr-windows-x86_64.exe	native	2.5 MiB	9.66 ms	9.87 ms
anyr.wasm	wasm	176.5 KiB	—	—

Budget check: ok

raw timings

[
  {
    "asset": "anyr-darwin-arm64",
    "kind": "native",
    "path": "/Users/runner/work/cli/cli/anyr-darwin-arm64",
    "bytes": 2905320,
    "size": "2.8 MiB",
    "version": "0.1.11 (built 2026-09-03 18:05:30)",
    "target": "aarch64-apple-darwin",
    "os": "macos-latest",
    "startup_version": {
      "n": 21,
      "min_ms": 5.19,
      "median_ms": 6.25,
      "p95_ms": 8.85,
      "mean_ms": 6.6
    },
    "startup_help": {
      "n": 21,
      "min_ms": 4.41,
      "median_ms": 6.15,
      "p95_ms": 9.45,
      "mean_ms": 8.04
    }
  },
  {
    "asset": "anyr-darwin-x86_64",
    "kind": "native",
    "path": "/Users/runner/work/cli/cli/anyr-darwin-x86_64",
    "bytes": 3119656,
    "size": "3.0 MiB",
    "version": "0.1.11 (built 2026-09-03 18:05:09)",
    "target": "x86_64-apple-darwin",
    "os": "macos-latest",
    "startup_version": {
      "n": 21,
      "min_ms": 34.01,
      "median_ms": 45.4,
      "p95_ms": 52.49,
      "mean_ms": 44.66
    },
    "startup_help": {
      "n": 21,
      "min_ms": 34.62,
      "median_ms": 38.2,
      "p95_ms": 50.78,
      "mean_ms": 40.23
    }
  },
  {
    "asset": "anyr-linux-arm64",
    "kind": "native",
    "path": "/home/runner/work/cli/cli/anyr-linux-arm64",
    "bytes": 2888744,
    "size": "2.8 MiB",
    "version": "0.1.11 (built 2026-09-03 18:04:57)",
    "target": "aarch64-unknown-linux-gnu",
    "os": "ubuntu-24.04-arm",
    "startup_version": {
      "n": 21,
      "min_ms": 0.72,
      "median_ms": 0.79,
      "p95_ms": 0.89,
      "mean_ms": 0.8
    },
    "startup_help": {
      "n": 21,
      "min_ms": 0.76,
      "median_ms": 0.8,
      "p95_ms": 0.85,
      "mean_ms": 0.8
    }
  },
  {
    "asset": "anyr-linux-x86_64",
    "kind": "native",
    "path": "/home/runner/work/cli/cli/anyr-linux-x86_64",
    "bytes": 3216904,
    "size": "3.1 MiB",
    "version": "0.1.11 (built 2026-09-03 18:04:39)",
    "target": "x86_64-unknown-linux-gnu",
    "os": "ubuntu-latest",
    "startup_version": {
      "n": 21,
      "min_ms": 0.79,
      "median_ms": 0.81,
      "p95_ms": 0.88,
      "mean_ms": 0.82
    },
    "startup_help": {
      "n": 21,
      "min_ms": 0.78,
      "median_ms": 0.8,
      "p95_ms": 0.9,
      "mean_ms": 0.81
    }
  },
  {
    "asset": "anyr-windows-x86_64.exe",
    "kind": "native",
    "path": "D:\\a\\cli\\cli\\anyr-windows-x86_64.exe",
    "bytes": 2665984,
    "size": "2.5 MiB",
    "version": "0.1.11 (built 2026-09-03T18:06:04Z)",
    "target": "x86_64-pc-windows-msvc",
    "os": "windows-latest",
    "startup_version": {
      "n": 21,
      "min_ms": 9.17,
      "median_ms": 9.66,
      "p95_ms": 9.86,
      "mean_ms": 9.64
    },
    "startup_help": {
      "n": 21,
      "min_ms": 9.48,
      "median_ms": 9.87,
      "p95_ms": 11.77,
      "mean_ms": 10.08
    }
  },
  {
    "asset": "anyr.wasm",
    "kind": "wasm",
    "path": "/home/runner/work/cli/cli/target/wasm-pkg/anyr_cli_bg.wasm",
    "bytes": 180713,
    "size": "176.5 KiB",
    "version": "wasm",
    "target": "wasm32-unknown-unknown",
    "os": ""
  }
]