added validation2, NEXT DO GRPCURL TESTING OF THE VALIDATIONS

common/proto/table_validation.proto

@@ -22,7 +22,7 @@ message FieldValidation {
   // Current: only CharacterLimits. More rules can be added later.
   CharacterLimits limits = 10;
   // Future expansion:
-  // PatternRules pattern = 11;
+  PatternRules pattern = 11; // Validation 2
   DisplayMask mask = 3;
   // ExternalValidation external = 13;
   // CustomFormatter formatter = 14;
@@ -57,6 +57,31 @@ message DisplayMask {
   optional string template_char = 3; // e.g., "_"
 }
 
+// One position‑based validation rule, similar to CharacterFilter + PositionRange
+message PatternRule {
+  // Range descriptor: how far the rule applies
+  // Examples:
+  //  - "0"        → Single position 0
+  //  - "0-3"      → Range 0..3 inclusive
+  //  - "from:5"   → From position 5 onward
+  //  - "0,2,5"    → Multiple discrete positions
+  string range = 1;
+
+  // Character filter type, case‑insensitive keywords:
+  // "ALPHABETIC", "NUMERIC", "ALPHANUMERIC",
+  // "ONEOF(<chars>)", "EXACT(:)", "CUSTOM(<name>)"
+  string filter = 2;
+}
+
+// Collection of pattern rules for one field
+message PatternRules {
+  // All rules that make up the validation logic
+  repeated PatternRule rules = 1;
+
+  // Optional human‑readable description for UI/debug purposes
+  optional string description = 2;
+}
+
 // Service to fetch validations for a table
 service TableValidationService {
   rpc GetTableValidation(GetTableValidationRequest)