bootstrap rules for go-factory-pattern.md (4 rules)

[bborbe]

Summary

• Migrates `docs/go-factory-pattern.md` from prose-only to rule-blocks-inline (Model A)
• Appends 4 `### RULE` blocks: 3 MUST mechanical + 1 MUST judgment
• Adds 3 `rules/go/*.yml` ast-grep detectors using field-based `has` clauses (the daemon's first pass invented invalid syntax; fixed in follow-up commit + smoke-verified)
• `rules/index.json` grows 13 → 17 entries
• Mirrors the proven 3-prior-PR bootstrap template

Rules added

ID	Level	Enforcement
`go-factory/no-error-return`	MUST	`rules/go/factory-no-error-return.yml`
`go-factory/no-conditional-in-body`	MUST	`rules/go/factory-no-conditional-in-body.yml`
`go-factory/no-cleanup-return`	MUST	`rules/go/factory-no-cleanup-return.yml`
`go-factory/no-impl-in-factory-pkg`	MUST	`judgment` (impl-vs-trivial-helper needs whole-method reasoning)

Scope: doc has ~10 distinct rules in the Checklist; this PR extracts 4 mechanically-tractable + 1 judgment. Skipped naming (Create*/New*), inline-business-logic overlap, boot-time validation, singletons, split-files — judgment-heavy or file-system checks.

Test plan

• `make precommit` clean
• `make build-index` deterministic
• 17 entries, sorted, anchor==id, owner=go-factory-pattern-assistant
• Judgment rule: `enforcement: judgment` literal
• Local ast-grep smoke against /tmp synthetic Bad/Good (9 functions):
  • Rule 1 hits 4 expected Bad (CreateBadA/B/D/E), 0 false positives
  • Rule 2 hits 1 expected Bad (CreateBadC with `if`), 0 false positives
  • Rule 3 hits 2 expected Bad (CreateBadD/E with func()), 0 false positives
  • NewServiceX (constructor) NOT flagged on any rule
• Operator-side post-merge: `scripts/scan.sh ~/Documents/workspaces/` against bborbe Go services

[ben-s-pull-request-reviewer]

Reviewed by ben-s-pull-request-reviewer[bot] — no concerns flagged.

[ben-s-pull-request-reviewer]

{
"verdict": "approve",
"summary": "The PR correctly bootstraps 4 new RULE blocks into go-factory-pattern.md (no-error-return, no-conditional-in-body, no-cleanup-return, no-impl-in-factory-pkg) with matching ast-grep YAML detectors and index.json entries. All three rule YAMLs are syntactically and semantically correct for ast-grep 0.43.0; the field-based `has` clauses are properly constructed. The index.json entries are well-structured with id, level (all MUST), owner, enforcement, applies_when, doc_path, and anchor fields. The RULE blocks have consistent owner, enforcement, why, and good/bad code examples. One environmental note: `make precommit` (link validation + JSON syntax check) could not be executed in this sandbox environment — it should be run locally before merging.",
"comments": [],
"concerns_addressed": [
"correctness: ast-grep YAML rules validated — field-based has-clauses are correct for ast-grep 0.43.0",
"correctness: index.json entries properly structured with id, level, owner, enforcement, applies_when, doc_path, anchor",
"correctness: RULE block IDs match filenames (factory-no-cleanup-return.yml → go-factory/no-cleanup-return, etc.)",
"correctness: docs/go-factory-pattern.md has 4 new RULE blocks with good/bad examples and enforcement paths",
"tests: no CI for ast-grep rules — documented as relying on local smoke test"
]
}