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/rules/cursor-meta.mdc

@@ -23,3 +23,17 @@ globs: [".cursor/**"]
 
 ## Security
 - All `.cursor/` files must be scanned for hidden Unicode before committing (see cursor-security.mdc)
+
+## Quality Thresholds (canonical reference)
+
+All rules and skills must reference the single source of truth below. Do NOT restate different numeric thresholds in individual rule or skill files.
+
+| Concern | Threshold | Enforcement |
+|---------|-----------|-------------|
+| Test coverage on business logic | 75% | Aim (warn below); 100% on critical paths |
+| Test scenario coverage (vs AC + restrictions) | 75% | Blocking in test-spec Phase 1 and Phase 3 |
+| CI coverage gate | 75% | Fail build below |
+| Lint errors (Critical/High) | 0 | Blocking pre-commit |
+| Code-review auto-fix | Low + Medium (Style/Maint/Perf) + High (Style/Scope) | Critical and Security always escalate |
+
+When a skill or rule needs to cite a threshold, link to this table instead of hardcoding a different number.