autosolve: Exit non-zero when implementation fails

Previously the implement binary exited 0 even on failure (all retries
exhausted, security check failed, PR creation failed), making the step
appear green. Now it writes outputs first so subsequent workflow steps
can still read them, then returns an error so the step is correctly
marked as failed.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: fantapop

autosolve/internal/implement/implement.go

@@ -158,8 +158,8 @@ func Run(
 			for _, v := range violations {
 				action.LogWarning(v)
 			}
-			action.LogWarning("Security check failed: violations found in staged changes")
-			return writeOutputs("FAILED", "", "", resultText, &tracker)
+			_ = writeOutputs("FAILED", "", "", resultText, &tracker)
+			return fmt.Errorf("security check failed: violations found in staged changes")
 		}
 		action.LogNotice("Security check passed")
 	}
@@ -170,8 +170,10 @@ func Run(
 		var err error
 		prURL, branchName, err = pushAndPR(ctx, cfg, runner, ghClient, gitClient, tmpDir, resultText, &tracker)
 		if err != nil {
-			action.LogWarning(fmt.Sprintf("PR creation failed: %v", err))
-			return writeOutputs("FAILED", "", "", resultText, &tracker)
+			// Write outputs before returning the error so status/summary are
+			// available to subsequent workflow steps.
+			_ = writeOutputs("FAILED", "", "", resultText, &tracker)
+			return fmt.Errorf("PR creation failed: %w", err)
 		}
 	}
 
@@ -186,7 +188,13 @@ func Run(
 		}
 	}
 
-	return writeOutputs(status, prURL, branchName, resultText, &tracker)
+	if err := writeOutputs(status, prURL, branchName, resultText, &tracker); err != nil {
+		return err
+	}
+	if status != "SUCCESS" {
+		return fmt.Errorf("implementation failed")
+	}
+	return nil
 }
 
 func pushAndPR(

autosolve/internal/implement/implement_test.go

@@ -181,10 +181,10 @@ func TestRun_AllRetriesFail(t *testing.T) {
 		results: []string{"IMPLEMENTATION_RESULT - FAILED", "IMPLEMENTATION_RESULT - FAILED"},
 	}
 
-	// Should not return error — just sets status to FAILED
+	// Should return an error so the step exits non-zero.
 	err := Run(context.Background(), cfg, runner, &mockGHClient{}, &mockGitClient{}, tmpDir)
-	if err != nil {
-		t.Fatal(err)
+	if err == nil {
+		t.Fatal("expected error when all retries fail")
 	}
 	if runner.calls != 2 {
 		t.Errorf("expected 2 calls, got %d", runner.calls)