chore(native): C ABI versioning rule + bump 0.5.0 → 0.6.0

[lotgon]

What

• Add src/native/collector/AGENTS.md (directory-scoped) documenting the collector's two version numbers:
  • C ABI version HSM_COLLECTOR_VERSION_* — bump MINOR for any added/changed exported hsm_* function (or appended struct field), MAJOR for breaking; same PR; keep CMakeLists.txt project VERSION in sync.
  • Product version HSM_COLLECTOR_PRODUCT_VERSION (the .module/Collector version sensor) — pinned to the managed HSMDataCollector.csproj <Version>; bump only at a DataCollector product release, in lockstep, never native-only.
• Bump the C ABI version 0.5.0 → 0.6.0 and resync CMakeLists.txt project(HsmCollectorNative VERSION …) (0.4.0 → 0.6.0).

Why

The C ABI policy (stated in hsm_collector.h + docs/native-collector-c-abi.md) requires a MINOR bump for every new exported function, but the recent wave — including #1221's hsm_collector_enable_file_logging — added functions since 0.5.0 (2026-06-27) without bumping. CMakeLists.txt had also drifted (0.4.0 vs header 0.5.0). One MINOR bump to 0.6.0 catches up the whole additive batch and resyncs both.

HSM_COLLECTOR_PRODUCT_VERSION stays 3.4.12 on purpose — it mirrors the managed collector (which had no release); the native logging is parity work, not a product release. To move the .module/Collector version sensor, both sides bump in lockstep at a real DataCollector release.

Notes

• No behavior change; version constants + a rules doc only.
• Companion to src/agent/AGENTS.md (the agent self-update versioning rule, chore(agent): self-update versioning rule + bump 0.5.24 → 0.5.25 #1222).

🤖 Generated with Claude Code

[github-actions]

PR #1224 Review — chore/collector-abi-version-rule

Summary

A small, well-scoped chore PR that:

1. Adds a directory-scoped src/native/collector/AGENTS.md documenting the collector's two independent version numbers (the C ABI semver HSM_COLLECTOR_VERSION_* vs. the product version HSM_COLLECTOR_PRODUCT_VERSION) and the rules for bumping each.
2. Bumps the C ABI version in hsm_collector.h (HSM_COLLECTOR_VERSION_MINOR 5 → 6) as the hygiene fix for the missed bump described as precedent feat(native): collector logging parity — built-in file logger + events + tests #1221.
3. Resyncs CMakeLists.txt project(... VERSION ...) 0.4.0 → 0.6.0 to match the header.

Overall this is a clean, correct, low-risk change. Verifications below.

Correctness — verified consistent ✅

• Header ↔ CMake now in sync. Baseline on master was header 0.5.0 and CMake 0.4.0 (drifted); after this PR both read 0.6.0. This is exactly what the AGENTS.md rule ("keep CMakeLists.txt in sync with the header macros") requires. ✅
• Product version correctly untouched. HSM_COLLECTOR_PRODUCT_VERSION stays "3.4.12", consistent with the stated policy that it moves only on a DataCollector product release. ✅
• No hardcoded version drift. The only consumer of the number, hsm_collector_version() in src/hsm_collector.cpp:5398, returns the HSM_COLLECTOR_VERSION macro directly, so it auto-updates. The self-check test (tests/hsm_collector_tests.cpp:2891, version() == HSM_COLLECTOR_VERSION) still holds, and the range assertion (:2892, MINOR >= 2) still passes at 6. ✅
• Packed value math MAJOR*10000 + MINOR*100 + PATCH = 600 for 0.6.0 — correct.
• Bump semantics are right: adding an exported function (hsm_collector_enable_file_logging, present in the header at line 318) is additive/backward-compatible, which correctly warrants a MINOR bump per the documented policy.

No bugs, security issues, or performance concerns — the diff only touches version literals and a new markdown doc.

Minor — maintainability

• Dangling doc reference. The new AGENTS.md (line 18) points to docs/native-collector-c-abi.md ("Policy is stated in the header and docs/native-collector-c-abi.md"), and the header (hsm_collector.h:12) already references the same path. That file does not exist anywhere in the repo (src/native/collector/docs/ is absent). The header's reference is pre-existing debt, but this PR adds a second pointer to a non-existent file. Consider either creating that doc (which the AGENTS.md implies is the canonical policy location) or trimming the references so the ABI policy has a single real home — otherwise a reader following the pointer hits nothing.

Note (not a defect)

• Retroactively bumping the ABI to 0.6.0 means the previously-shipped 0.5.0 is slightly ambiguous (it exists both with and without the file-logging function, since feat(native): collector logging parity — built-in file logger + events + tests #1221 added the function under 0.5.0). Given the collector is at major 0 and there are no external versioned find_package(hsm_collector x.y ...) consumers in-repo (both test_package/ and examples/console/standalone/ request it without a version, under COMPATIBILITY SameMajorVersion), this hygiene correction is harmless. Flagging only for awareness.

Verdict: Approve. The version bump is correct and consistent across header, CMake, runtime, and tests. Suggest addressing the dangling docs/native-collector-c-abi.md reference (pre-existing, but this PR reinforces it).