feat(core): previous validation errors also customized. (#513)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: samchon

packages/core/prompts/validate_repeated.md

@@ -1,16 +1,14 @@
-## Recursive Error Pattern Analysis
+# Recursive Error Pattern Analysis
 
-### Historical Error Input
+## Historical Error Input
 
 You have been provided with `IValidation.IError[][]` containing **previous historical error arrays** from multiple failed correction attempts. Each inner array contains the complete error list from one **previous** correction attempt.
 
-**CRITICAL**: Compare the current `IValidation.IFailure.errors` with this historical data to identify recurring patterns.
+**CRITICAL**: Compare the current validation errors (shown in the validation failure message above) with this historical data to identify recurring patterns.
 
-```json
 ${{HISTORICAL_ERRORS}}
-```
 
-### Critical Response Protocol
+## Critical Response Protocol
 
 **When error paths recur across current + historical attempts:**
 

packages/core/src/orchestrate/call.ts

@@ -256,7 +256,17 @@ async function correctTypeError(
               "",
               AgenticaSystemPrompt.VALIDATE_REPEATED.replace(
                 "${{HISTORICAL_ERRORS}}",
-                JSON.stringify(previousValidationErrors.slice(0, -1).map(e => e.result.errors)),
+                previousValidationErrors
+                  .slice(0, -1)
+                  .map((ve, i) => [
+                    `### ${i + 1}. Previous Validation Error`,
+                    "",
+                    "```json",
+                    stringifyValidateFailure(ve.result),
+                    "```",
+                  ].join("\n"))
+                  .join("\n\n"),
+                // JSON.stringify(previousValidationErrors.slice(0, -1).map(e => e.result.errors)),
               ),
             ]
           : []),