improved zone handling

AI_dev_plan.md

@@ -108,6 +108,34 @@ Must-have plan is complete when all are true:
 2. Feature PRs without spec updates are blocked.
 3. Backend router contracts cover core success and error paths.
 4. Frontend has at least one stable test command integrated into validation.
+
+## 7. AI Tools Validation Strategy
+
+Required:
+
+1. **Per-edit validation**: After each code change (file edit, replacement, or creation), validate immediately with appropriate tools.
+2. **Tool selection by change type**:
+   - Frontend changes: ESLint (`npm run -s lint`), then TypeScript build (`npm run build`)
+   - Backend changes: Syntax check via Python import, then run relevant test suite
+   - Type/interface changes: Full type check via build or `tsc -b`
+3. **Failure handling**: If validation fails, fix immediately before proceeding to next edit.
+4. **Documentation updates**: When changing architecture, always update [.github/copilot-instructions.md](.github/copilot-instructions.md) as part of the same PR.
+5. **Large multi-edit operations**: Use `multi_replace_string_in_file` to batch independent edits and reduce tool call overhead.
+6. **Error collection**: Use `get_errors` tool to identify issues across multiple files in one call post-change.
+
+Current implementation:
+
+1. Electron removal completed with post-edit lint and build validation at each phase.
+2. Zone editor feature implemented with immediate lint/build validation after component creation and UI integration.
+3. Validation tools: `npm run -s lint`, `npm run build`, `get_errors`, `run_in_terminal` for test scripts.
+
+Best practices established:
+
+- Always run lint before build to catch TypeScript errors early
+- Run full build after component changes to verify tree-shaking and bundling
+- Use `get_errors` for multi-file error detection rather than sequential file reads
+- Batch unrelated edits with `multi_replace_string_in_file` for efficiency
+- Cache key decisions in session memory to avoid repeated exploration
 5. AI policy + diagnostics workflow are active.
 
 ## Current State Summary