Add CMFRT coding standards documentation and examples

- Introduced guidelines for "one codeunit one global function" architecture to enforce single responsibility in AL code.
- Added best practices and anti-patterns for adding parameters via overloads to maintain backward compatibility.
- Documented the importance of never deleting members in AL and always marking them as obsolete.
- Established the requirement for OnBefore and OnAfter integration events for global procedures to enhance extensibility.
- Defined naming conventions for CMFRT objects, including prefixes and object ID ranges to avoid conflicts.
- Implemented patterns for case statements to ensure all cases are handled, including the necessity of an else clause.
- Introduced the interface injection pattern to allow pluggable operations in table-level code.
- Recommended using Confirm Management for user confirmations to improve testability.
- Established a three-permission set pattern for security to ensure proper access control.
- Created a review skill for CMFRT AL standards to automate compliance checks against established guidelines.

custom/knowledge/breaking-changes/cmfrt-never-delete-always-obsolete.bad.al

@@ -0,0 +1,15 @@
+// Field deleted outright — any upgrade codeunit or dependent extension
+// that referenced "CMFRT GD Error Path" will fail to compile.
+table 2045085 "CMFRT GD Setup"
+{
+    fields
+    {
+        field(1; "Primary Key"; Code[10]) { DataClassification = SystemMetadata; }
+        field(2; "CMFRT GD ErrorPath"; Text[500])
+        {
+            Caption = 'Error Path';
+            DataClassification = CustomerContent;
+        }
+        // "CMFRT GD Error Path" (field 2045325) was deleted here — breaking change.
+    }
+}