Add DRY, dependency and SOLID criteria to the code checklists (MIL-009 task 5)

New criteria, appended after the existing ones (nothing renumbered or
changed):

- DRY in all five qc-programming-* checklists (python, c, cpp, csharp, shell)
- dependency rule in all but shell (imports, includes or references point
  inward, no cycles; in C also one responsibility per module)
- SOLID in python, cpp and csharp
- qc-dcd.md criterion 9: dependencies between classes and packages point
  inward (cycles stay with criterion 8)

Each is tagged with an ISO/IEC 25010 characteristic, and the criterion Notes
name the rule in the framework's coding-conventions skill, which defines it
once. Each checklist has a new Proposed Version History row for S02, who
accepts coding-standard changes. Common Defects gain a bullet per criterion.

qc-programming-c.md

@@ -11,6 +11,7 @@
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-01 | Accepted | Jens Tirsvad Nielsen | S07 | First public release (1.0.0) | — |
+| 2026-10-09 | Proposed | Jens Tirsvad Nielsen | S02 | Added criteria 14 to 15 (DRY and dependency rule) | pending |
 
 ---
 
@@ -37,6 +38,8 @@ Level: **Mandatory** criteria are the baseline every instance must meet; **Optio
 | 11 | Error reporting (status codes, `errno` use) is documented in the header | Optional | Usability, Reliability | |
 | 12 | Tests cover new behaviour and run under address and undefined-behaviour sanitizers in at least one build | Optional | Reliability, Security | |
 | 13 | Modules and functions trace to the Design Class Diagram or design artifact they implement | Mandatory | Functional Suitability, Maintainability | |
+| 14 | Each piece of knowledge (a business rule, constant, format, validation or query) is defined in one place; code is merged only where it expresses the same knowledge, not where it merely looks alike | Mandatory | Maintainability | Modularity, Reusability. Rule: `coding-conventions` skill, “State each piece of knowledge once” |
+| 15 | Includes point inward: business-rule modules include no I/O, platform or UI headers, the include graph has no cycles, and a module has one responsibility (rules are not mixed with I/O) | Mandatory | Maintainability, Portability | Modularity, Portability. Rule: `coding-conventions` skill, “Dependencies point inward” |
 
 ## Common Defects
 
@@ -47,6 +50,9 @@ Level: **Mandatory** criteria are the baseline every instance must meet; **Optio
 - Macros doing the work of `static inline` functions or `enum`
 - Identifiers starting with an underscore and an uppercase letter
 - Undefined behaviour hidden by a build that happens to work
+- The same rule, constant or table written in two modules
+- A business-rule module that includes a platform, I/O or UI header, or modules that include each other
+- A module that mixes business rules with file or device access
 
 ## Traceability Rule