table definition column types is shared

common/proto/table_definition.proto

@@ -27,6 +27,10 @@ service TableDefinition {
   // This provides a tree-like overview of table relationships.
   rpc GetProfileTree(komp_ac.common.Empty) returns (ProfileTreeResponse);
 
+  // Lists every column type a table may declare, along with the SQL type it
+  // maps to. Pure data retrieval - no business logic.
+  rpc ListColumnTypes(komp_ac.common.Empty) returns (ListColumnTypesResponse);
+
   // Fetches all tables with their columns and scripts for a specific profile.
   // Pure data retrieval - no business logic.
   rpc GetProfileDetails(GetProfileDetailsRequest) returns (GetProfileDetailsResponse);
@@ -357,3 +361,19 @@ message DeleteTableResponse {
   // Human-readable summary of what was removed.
   string message = 2;
 }
+
+// Response listing every column type a table may declare.
+message ListColumnTypesResponse {
+  // One declared column type and the SQL type it maps to.
+  message ColumnType {
+    // Logical column type (e.g. "money", "instant"). Passed to the server as
+    // ColumnDefinition.field_type.
+    string name = 1;
+
+    // Underlying PostgreSQL type the logical type maps to (e.g. "NUMERIC").
+    string sql_type = 2;
+  }
+
+  // All declared column types.
+  repeated ColumnType column_types = 1;
+}