fix(server): surface validation errors in 2-14 fix-standard-relation-field-labels-icons upgrade command (#21658)

## Problem

The \`2-14:fix-standard-relation-field-labels-icons\` workspace upgrade
command threw a generic error on migration build failure:

\`\`\`ts
if (result.status === 'fail') {
throw new Error(\`Migration failed for workspace \${workspaceId} while
healing standard relation field labels/icons\`);
}
\`\`\`

This discarded \`result.report\` entirely — the structured per-field
validation failures (\`code\`, \`message\`, \`value\`, offending field)
— making real-world upgrade failures impossible to diagnose from logs.
On a recent staging/app-main upgrade, 13 workspaces failed here with no
actionable detail.

## Change

Flatten \`result.report\` into both the logged error and the thrown
message, so failures now print the actual validation errors per field,
e.g.:

\`\`\`
[fieldMetadata] <universalIdentifier> -> SOME_VALIDATION_CODE: <real
reason>
\`\`\`

No behavior change beyond logging/error content — the command still
aborts on failure as before.

## Notes

- Dry-run still returns before the build step, so this only surfaces on
real runs (unchanged).

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packages/twenty-server/src/database/commands/upgrade-version-command/2-14/2-14-workspace-command-1799000040000-fix-standard-relation-field-labels-icons.command.ts

@@ -136,8 +136,23 @@ export class FixStandardRelationFieldLabelsIconsCommand extends ActiveOrSuspende
       );
 
     if (result.status === 'fail') {
+      const failureDetails = Object.values(result.report)
+        .flat()
+        .map((failedValidation) => {
+          const errorMessages = failedValidation.errors
+            .map((error) => `${error.code}: ${error.message}`)
+            .join('; ');
+
+          return `[${failedValidation.metadataName}] ${failedValidation.flatEntityMinimalInformation.universalIdentifier ?? failedValidation.flatEntityMinimalInformation.id ?? 'unknown'} -> ${errorMessages}`;
+        })
+        .join('\n');
+
+      this.logger.error(
+        `Migration build failed for workspace ${workspaceId} while healing standard relation field labels/icons:\n${failureDetails}`,
+      );
+
       throw new Error(
-        `Migration failed for workspace ${workspaceId} while healing standard relation field labels/icons`,
+        `Migration failed for workspace ${workspaceId} while healing standard relation field labels/icons:\n${failureDetails}`,
       );
     }