fix(cli): speed up standalone version queries

[kunchenguid]

Intent

Adopt the axi-sdk-js/fast-path in tasks-axi so tasks-axi --version hits the node floor (~31ms -> ~20ms), per the shared spec at /Users/kunchen/fm-homes/axi-a1/data/p4-fastpath-adoption-spec.md.

Required work:

1. Bump the axi-sdk-js dependency range to include 0.1.10 (so the dependency-free axi-sdk-js/fast-path subpath export resolves) and install.
2. tasks-axi computed its version inside src/cli.ts (a readPackageVersion() helper). Extract it into a LEAF src/version.ts that imports ONLY node builtins - never the heavy command graph - and re-import VERSION from it in cli.ts, so there is still one source of the version string.
3. Rewrite bin/tasks-axi.ts to the exact benchmarked fast-path shape: import tryFastPath from axi-sdk-js/fast-path and VERSION from the leaf module; if tryFastPath(process.argv.slice(2), {version: VERSION}) returns false, await import("../src/cli.js") (dynamic, so the heavy graph loads only there) and await main().
4. Keep the fast path conservative: exactly one argv element that is -v/-V/--version. Any other form (including a version flag in a trailing position such as list --version) falls through to runAxiCli, which remains the sole owner of the general case - list --version is still an unknown-flag validation error, exactly as before.

Hard constraints from the requester: firstmate's own backlog runs on tasks-axi, so --version output must stay byte-identical and NO command behavior may change - this is only the version fast path.

Regression-test approach mandated by the spec (deliberate decisions, not oversights):

• A deterministic module-trace guard: an ESM loader hook (test/fixtures/module-trace-*.mjs) records every module URL the spawned bin process loads, and test/bin/version-fast-path.test.ts asserts src/cli.ts, axi-sdk-js/dist/index.js and @toon-format are absent on the --version path while the fast-path module and the leaf version module are present.
• A NEGATIVE CONTROL proving the probe would catch a regression: --help, list --help and list --version must each still load the heavy graph.
• Flag parity: -v, -V and --version each print exactly ${version}\n and exit 0, matching the pre-change output byte-for-byte.
• DELIBERATELY NO wall-clock timing assertion in CI (neither absolute nor delta). A sibling task proved that flaky across CI runners (15ms and 30ms budgets both failed under contention). The module trace deterministically proves the heavy graph is skipped, which is the real mechanism of the speedup and the correct thing to assert. Do not add a timing gate.

The tests spawn the TypeScript bin via node --import tsx --import <register> bin/tasks-axi.ts rather than the built dist output, so the guard runs without requiring a prior build and exercises the sources under test.

AXI ergonomics must be preserved (per the axi skill). AGENTS.md gained a short 'Entry point & the --version fast path' section recording the leaf-module invariant and the no-timing-in-CI rule.

What Changed

• Route standalone -v, -V, and --version requests through axi-sdk-js/fast-path, deferring the full CLI command graph for all other arguments.
• Extract package-version resolution into a Node-only leaf module and update axi-sdk-js to ^0.1.10.
• Add deterministic module-trace coverage for fast-path isolation, version-output parity, and full-CLI fallthrough behavior.

Pipeline

Updates from git push no-mistakes

✅ **intent** - passed

✅ **Rebase** - passed

✅ **Review** - completed

✅ **Test** - passed

✅ **Document** - passed

✅ **Lint** - passed

✅ **Push** - passed