#21695: fix(edit): include line numbers in duplicate match errors

## Summary Enhances the edit tool error message to include line numbers when multiple occurrences of `oldText` are found, enabling agents to recover by reading the relevant lines and expanding `oldText` with surrounding context. ## Problem When the `edit` tool finds more than one occurrence of `old_string`, it returns: ``` Found 2 occurrences of the text in <file>. The text must be unique. Please provide more context to make it unique. ``` This is correct behavior — ambiguous edits should be rejected. However, the error gives the agent **no actionable information** to recover with. The agent knows it needs more context, but doesn't know *where* in the file the duplicates are, so it can't easily construct a larger unique `old_string`. In practice, agents (Codex, Claude Code) tend to **give up and stop** rather than retry with expanded context, because the retry requires reading the whole file and manually finding surrounding lines. ## Changes The error message now includes the **line numbers** where the duplicate matches were found: ``` Found 2 occurrences of the text in <file> (lines 284, 292). The text must be unique. Please provide more context to make it unique. ``` With line numbers, an agent can: 1. Immediately read only the relevant lines 2. Expand `old_string` to include the surrounding function signature (which is unique) 3. Retry the edit successfully — without reading the entire file ## Implementation - Added `wrapEditToolWithLineNumbers` wrapper function in `src/agents/pi-tools.read.ts` - Intercepts "Found X occurrences" errors from the base edit tool - Reads the file and finds all line numbers where `oldText` appears (supports multi-line text) - Enhances the error message with line numbers (truncates to first 5 if more than 5 total) - Falls back to original error if enhancement fails ## Tests Added `src/agents/pi-tools.read.edit-line-numbers.test.ts` with test cases: - Single-line duplicate text - Multi-line duplicate text - Many occurrences (truncation test) - Unique text (normal operation) All tests pass ✅ Fixes #21645 <!-- greptile_comment --> <h3>Greptile Summary</h3> This PR enhances the edit tool error messaging by adding line numbers when duplicate text matches are found. When an edit operation fails due to multiple occurrences of `oldText`, the error now includes line numbers (e.g., "Found 2 occurrences... (lines 3, 5)") instead of just the count. This enables agents to immediately identify where duplicates exist and expand `oldText` with surrounding context to make it unique. The implementation uses a wrapper function that intercepts duplicate match errors, reads the file to find all occurrence line numbers, and reconstructs the error message with this additional context. The wrapper handles multi-line text correctly and truncates to show only the first 5 line numbers if there are more than 5 occurrences. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge - it's a non-breaking enhancement with solid test coverage - The change is well-isolated (wrapper pattern), thoroughly tested with 4 test cases covering single-line, multi-line, truncation, and normal operation scenarios. The error handling is defensive with fallback to original error if enhancement fails. No breaking changes to existing functionality. - No files require special attention _{Last reviewed commit: 6ec8597} <!-- greptile_other_comments_section --> <!-- /greptile_comment -->