fix(crafter): address review feedback - revert PR metadata, simplify AI config filename

- Revert collector_prmetadata.go: PR metadata intentionally uses PR
  number for naming; deduplication within the same PR is expected
- Restore collector_prmetadata_test.go deleted by mistake
- Simplify AI config temp filename to a constant name per agent
  (ai-agent-config-{agentName}.json) instead of appending the full
  64-character ConfigHash

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Vibhav Bobade <vibhav.bobde@gmail.com>

Author: waveywaves

pkg/attestation/crafter/collector_aiagentconfig.go

@@ -100,17 +100,15 @@ func (c *AIAgentConfigCollector) uploadAgentConfig(
 		return fmt.Errorf("marshaling AI agent config for %s: %w", agentName, err)
 	}
 
-	// Use a deterministic filename derived from the config hash so that retries
-	// produce the same Artifact.Name (via fileStats -> os.Stat().Name()) and
-	// avoid duplicate CAS uploads. PR #2917 fixed the primary root cause
-	// (non-deterministic content from captured_at); this is additional hardening.
-	tmpPath := filepath.Join(os.TempDir(), fmt.Sprintf("ai-agent-config-%s-%s.json", agentName, data.ConfigHash))
+	// Use a constant filename per agent so retries produce the same
+	// Artifact.Name (via fileStats -> os.Stat().Name()).
+	materialName := fmt.Sprintf("ai-agent-config-%s", agentName)
+	tmpPath := filepath.Join(os.TempDir(), fmt.Sprintf("%s.json", materialName))
 	if err := os.WriteFile(tmpPath, jsonData, 0o600); err != nil {
 		return fmt.Errorf("writing temp file: %w", err)
 	}
 	defer os.Remove(tmpPath)
 
-	materialName := fmt.Sprintf("ai-agent-config-%s", agentName)
 	if _, err := cr.AddMaterialContractFree(ctx, attestationID, schemaapi.CraftingSchema_Material_CHAINLOOP_AI_AGENT_CONFIG.String(), materialName, tmpPath, casBackend, nil); err != nil {
 		return fmt.Errorf("adding AI agent config material for %s: %w", agentName, err)
 	}

pkg/attestation/crafter/collector_prmetadata.go

@@ -17,12 +17,9 @@ package crafter
 
 import (
 	"context"
-	"crypto/sha256"
-	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"os"
-	"path/filepath"
 
 	schemaapi "github.com/chainloop-dev/chainloop/app/controlplane/api/workflowcontract/v1"
 	"github.com/chainloop-dev/chainloop/internal/prinfo"
@@ -72,22 +69,40 @@ func (c *PRMetadataCollector) Collect(ctx context.Context, cr *Crafter, attestat
 		return fmt.Errorf("marshaling PR/MR metadata: %w", err)
 	}
 
-	// Use a deterministic filename derived from a hash of the content so that
-	// retries produce the same Artifact.Name (via fileStats -> os.Stat().Name())
-	// and avoid duplicate CAS uploads.
-	contentHash := sha256.Sum256(jsonData)
-	materialName := fmt.Sprintf("pr-metadata-%s", metadata.Number)
-	tmpPath := filepath.Join(os.TempDir(), fmt.Sprintf("%s-%s.json", materialName, hex.EncodeToString(contentHash[:])))
-	if err := os.WriteFile(tmpPath, jsonData, 0o600); err != nil {
-		return fmt.Errorf("writing temp file: %w", err)
+	materialName, tmpFile, err := createPRMetadataTempFile(metadata.Number, jsonData)
+	if err != nil {
+		return fmt.Errorf("creating PR metadata temp file: %w", err)
 	}
-	defer os.Remove(tmpPath)
+	defer os.Remove(tmpFile)
 
-	if _, err := cr.AddMaterialContractFree(ctx, attestationID, schemaapi.CraftingSchema_Material_CHAINLOOP_PR_INFO.String(), materialName, tmpPath, casBackend, nil); err != nil {
+	if _, err := cr.AddMaterialContractFree(ctx, attestationID, schemaapi.CraftingSchema_Material_CHAINLOOP_PR_INFO.String(), materialName, tmpFile, casBackend, nil); err != nil {
 		return fmt.Errorf("adding PR/MR metadata material: %w", err)
 	}
 
 	cr.Logger.Info().Msg("successfully collected and attested PR/MR metadata")
 
 	return nil
 }
+
+// createPRMetadataTempFile creates a temp file with the PR metadata JSON content
+// and returns the material name and the temp file path.
+func createPRMetadataTempFile(prNumber string, data []byte) (materialName string, filePath string, err error) {
+	materialName = fmt.Sprintf("pr-metadata-%s", prNumber)
+
+	tmpFile, err := os.CreateTemp("", fmt.Sprintf("%s-*.json", materialName))
+	if err != nil {
+		return "", "", fmt.Errorf("creating temp file: %w", err)
+	}
+
+	if _, err := tmpFile.Write(data); err != nil {
+		tmpFile.Close()
+		os.Remove(tmpFile.Name())
+		return "", "", fmt.Errorf("writing temp file: %w", err)
+	}
+	if err := tmpFile.Close(); err != nil {
+		os.Remove(tmpFile.Name())
+		return "", "", fmt.Errorf("closing temp file: %w", err)
+	}
+
+	return materialName, tmpFile.Name(), nil
+}

pkg/attestation/crafter/collector_prmetadata_test.go

@@ -0,0 +1,66 @@
+//
+// Copyright 2026 The Chainloop Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crafter
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreatePRMetadataTempFile(t *testing.T) {
+	tests := []struct {
+		name           string
+		prNumber       string
+		wantMaterial   string
+		wantFilePrefix string
+	}{
+		{
+			name:           "numeric PR number",
+			prNumber:       "123",
+			wantMaterial:   "pr-metadata-123",
+			wantFilePrefix: "pr-metadata-123-",
+		},
+		{
+			name:           "large PR number",
+			prNumber:       "99999",
+			wantMaterial:   "pr-metadata-99999",
+			wantFilePrefix: "pr-metadata-99999-",
+		},
+		{
+			name:           "single digit PR number",
+			prNumber:       "1",
+			wantMaterial:   "pr-metadata-1",
+			wantFilePrefix: "pr-metadata-1-",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			materialName, filePath, err := createPRMetadataTempFile(tc.prNumber, []byte(`{"test": true}`))
+			require.NoError(t, err)
+			defer os.Remove(filePath)
+
+			assert.Equal(t, tc.wantMaterial, materialName)
+			assert.Equal(t, ".json", filepath.Ext(filePath))
+			assert.True(t, strings.HasPrefix(filepath.Base(filePath), tc.wantFilePrefix))
+		})
+	}
+}