Refine coding standards and testing guidelines

- Updated coding rule descriptions for clarity and emphasis on readability, meaningful comments, and test verification.
- Adjusted thresholds for test coverage on business logic from 80% to 75%, aligning with the canonical reference in `cursor-meta.mdc`.
- Enhanced guidelines for handling skipped tests, emphasizing the need for investigation and classification.
- Introduced completeness audit requirements for research decomposition to ensure thoroughness in addressing problem dimensions.

.cursor/skills/research/references/quality-checklists.md

@@ -10,6 +10,12 @@
 - [ ] Every citation can be directly verified by the user (source verifiability)
 - [ ] Structure hierarchy is clear; executives can quickly locate information
 
+## Decomposition Completeness
+
+- [ ] Domain discovery search executed: searched "key factors when [problem domain]" before starting research
+- [ ] Completeness probes applied: every probe from `references/comparison-frameworks.md` checked against sub-questions
+- [ ] No uncovered areas remain: all gaps filled with sub-questions or justified as not applicable
+
 ## Internet Search Depth
 
 - [ ] Every sub-question was searched with at least 3-5 different query variants