Add FP gold answers: page-effective-filter and page-boolean-triggers

[gggdttt]

What

Adds two code-review negative-example gold answers to dataset/codereview.jsonl that lock in BCQuality precision guards from PR #112 as offline regressions. Both are new-files-only synthetic entries with expected_comments: [] — any finding the agent emits on them costs precision.

Entries

instance_id	area	Guard exercised	Derived from
synthetic__perf-clean-01	performance	performance/page-effective-filter-may-live-outside-the-diff	online-eval FP cluster PR 8124
synthetic__error-clean-01	error-handling	error-handling/page-boolean-triggers-default-to-true	online-eval FP cluster PR 8419

• perf-clean-01 — a warehouse activities cue field uses DrillDownPageId to a list page whose SourceTableView already filters the result set (Status = Open), matching the cue FlowField's own filter. The effective filter lives on the drill-down page, outside the changed field's hunk, so the drill-down is not unfiltered. A "drills down to an unfiltered/full-table list" finding is a false positive.
• error-clean-01 — a card page's OnInsertRecord/OnModifyRecord triggers do work but omit an explicit exit(true). Page Boolean record triggers return true by default, so the insert/modify still proceeds. A "returns false, blocking all inserts / discards all edits" finding is a false positive.

Validation

• Real loader accepts the file: CodeReviewEntry.load(...) → 102 entries, both new ids present.
• Both patches git apply --check clean against base 70fd0246a0a4dbc72cb183ca719106722c03be4d.
• No explanatory comments in the synthetic AL (intent encoded in code shape only).

Part of the BC apps negative-feedback batch-1 gold-answer set (tracked in ADO 639657). Companion to #745 (tooltip inheritance) and #746 (unreleased schema).