Refine coding standards and testing guidelines

- Updated the coding rule descriptions to emphasize readability, meaningful comments, and test verification.
- Revised guidelines to clarify the importance of avoiding boilerplate while maintaining readability.
- Enhanced the testing rules to set a minimum coverage threshold of 75% for business logic and specified criteria for test scenarios.
- Introduced a mechanism for handling skipped tests, categorizing them as legitimate or illegitimate, and outlined resolution steps.

These changes aim to improve code quality, maintainability, and testing effectiveness.

.cursor/skills/autopilot/SKILL.md

@@ -55,6 +55,11 @@ After selecting the flow, apply its detection rules (first match wins) to determ
 Every invocation follows this sequence:
 
 ```
+0. Process leftovers (see `.cursor/rules/tracker.mdc` → Leftovers Mechanism):
+   - Read _docs/_process_leftovers/ if it exists
+   - For each entry, attempt replay against the tracker
+   - Delete successful replays, update failed ones with new timestamp + reason
+   - If any leftover still blocked AND requires user input → STOP and ASK
 1. Read _docs/_autopilot_state.md (if exists)
 2. Read all File Index files above
 3. Cross-check state file against _docs/ folder structure (rules in state.md)