2606071930_arch-fix-tablereadability-dup.md

id	2606071930
title	Consolidate duplicated table-parse helpers in tablereadability
status	✅
summary	Move tablereadability's private findTables/tryParseTable into tablefmt so the two rules share one copy.
model	sonnet
depends-on

Consolidate duplicated table-parse helpers

Goal

Remove duplicated findTables and tryParseTable from internal/rules/tablereadability/rule.go by sharing the boundary-detection logic already in internal/rules/tablefmt.

Background

Both tablereadability and tablefmt carry private copies of findTables and tryParseTable. The copies diverged on the perf pass (1ee98e7). Future perf or correctness fixes risk being applied to one copy and missed in the other.

The two table types differ. tablefmt.table stores cells []string for formatting. tablereadability.tableRow stores cells [][]byte for zero-alloc counting. A clean consolidation exports boundary detection separately from cell parsing. Or it accepts distinct table types with a shared scanner.

Severity: tax (DRY violation; copies diverge on every perf pass).

Tasks

1. Export a table-boundary scanner from tablefmt — a helper that returns start/end indices of each table block without parsing cells.
2. Update tablereadability to call the exported scanner and parse cells itself from the detected line ranges.
3. Add or update unit tests in both packages.
4. Verify TestRulesDoNotImportEachOther still passes.
5. Verify no regression: go test ./....

Acceptance Criteria

• Table-boundary scanning exists in one package only.
• tablereadability does not duplicate scanning logic.
• TestRulesDoNotImportEachOther passes.
• All tests pass: go test ./...
• go tool golangci-lint run reports no issues