## Summary
- Add new `search_replace` tool with strict matching requirements:
  - Requires minimum 3 lines of context for unambiguous matching
  - Enforces exact-only matching (no fuzzy/lenient fallback)
  - Rejects ambiguous matches and identical old/new strings
- Extend `applySearchReplace` processor with `SearchReplaceOptions`
interface
- Update system prompt with file editing tool selection guidelines
- Add comprehensive unit tests (43 tests) and E2E test

## Test plan
- Unit tests: `npm run test -- search_replace` (43 tests passing)
- E2E tests: `npm run e2e -- --grep "local-agent"` (19 tests passing)
- Verify lint passes: `npm run fmt && npm run lint && npm run ts`

🤖 Generated with [Claude Code](https://claude.com/claude-code)
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<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Introduces a precise, single-instance `search_replace` tool for local
agent edits and wires it across stack.
> 
> - New `search_replace` tool: strict schema (`file_path`, `old_string`,
`new_string`), rejects identical/ambiguous matches, streams XML, deploys
Supabase functions when applicable; registered in `tool_definitions`
> - Processor overhaul: replace Levenshtein with cascading matching
(exact → whitespace-tolerant → unicode-normalized), detailed failure
diagnostics, marker escaping helper, async fs usage
> - Update `edit_file` schema/usage from `description` → `instructions`
(tool schema, XML builder, examples)
> - Prompt: add file-editing tool selection guidance and post-edit
verification
> - UI: `DyadSearchReplace` gains `data-testid="dyad-search-replace"`
for E2E visibility
> - Tests: comprehensive unit tests for processor and tool, DSL runner
with pass/fail suites, plus new Playwright E2E and fixtures; snapshots
updated
> - Chore: remove `fastest-levenshtein` dependency from
`package.json`/lockfile
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
dfa9b9e172e89f135fc71cd1f35f7f3c614b9af4. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

<!-- This is an auto-generated description by cubic. -->
---
## Summary by cubic
Adds a strict search_replace tool for precise, single-instance file
edits by the local agent. Enforces exact matches with ≥3 non-empty lines
of context and auto-deploys Supabase functions when server functions are
edited.

- New search_replace tool: exact-only matching, requires ≥3 non-empty
lines of context, rejects ambiguous matches, and disallows identical
old/new strings
- Processor: implement cascading matching passes; add
SearchReplaceOptions (exactMatchOnly, rejectIdentical) and wire into
applySearchReplace
- Prompt: add clear edit-tool selection guidance, post-edit
verification, and write_file fallback
- Tests: comprehensive unit tests plus an E2E covering the new tool;
snapshots updated
- UI: add data-testid to surface search-replace actions and register the
tool in definitions
- Dependencies: remove fastest-levenshtein
- Edit tool: rename description → instructions in the schema and XML;
examples and prompt updated

<sup>Written for commit dfa9b9e172e89f135fc71cd1f35f7f3c614b9af4.
Summary will update on new commits.</sup>

<!-- End of auto-generated description by cubic. -->

---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>