CONV009 threshold is hard-coded at 15; the lint-config options example does nothing #267

What broke:
CONV009 (MaxMicroflowObjects) cannot be tuned, though the project's .claude/lint-config.yaml says it can.

• The rule is mxcli's bundled conv009_max_microflow_objects.star, seeded by mxcli init. Line 13 is MAX_ACTIVITIES = 15, a constant. The rule never calls get_option().
• The lint-config.yaml that mxcli init writes shows this exact rule as its example: CONV009: … options: maxObjects: 20. mxcli does pass options to Starlark rules (get_option(key, default) exists, and missing_documentation.star and conv018 use it). CONV009 ignores them, so following the example changes nothing. No error, no notice.
• The threshold conflicts with the toolkit's own guidance. skills/microflow-preflight.md sets the split trigger at 20 activities, counting loop bodies. CONV009 fires at 15 and counts top-level activities only. It also overlaps QUAL003 (25).

Command / script run:
mxcli lint with the stock rule and the config example uncommented (rules: CONV009: options: maxObjects: 20). Findings stay at the 15-activity threshold.

Field evidence:
Three toolkit-built apps, mxcli v0.25.0. All three ship rules: {}, so nothing was tuned anyway. CONV009 findings were 36 / 30 / 5. At 20 they would be 16 / 11 / 2, which is the list of microflows a reviewer actually wanted split. One app ran a script whose only purpose was to split flows below 15 to satisfy the linter. The CONV009 rises were re-baselined in bulk (one commit: "CONV009 +10").

Proposal:

1. Toolkit: ship a conv009_max_microflow_objects.star through the existing replace-the-stock path (MXTK_LINT_RULES + STOCK-HASHES.txt, same as CONV010) that reads get_option("maxObjects", 20). The default of 20 matches microflow-preflight.md. Stock hashes for v0.17/0.24/0.25 are needed so a re-seed is recognised.
2. Upstream mxcli (not filed here): the bundled rule should read the option its own generated config advertises.
3. Until then, lint-that-actually-runs.md should say that options: reaches only rules that call get_option, and that CONV009 is not one of them.

Not in PR #266, because changing a default threshold for every project is a maintainer call.