fix(#337): Return error state from secret scanner on scan failures

- Add scanError field and scannedSuccessfully flag to SecretScanResult
- File read errors no longer falsely report as "clean"
- Callers can distinguish clean files from scan failures
- Update getScanSummary to track filesWithErrors count
- SecretsDetectedError now reports files that couldn't be scanned
- Add tests verifying error handling behavior for file access issues

Refs #337

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/orchestrator/src/git/secret-scanner.service.spec.ts

@@ -392,11 +392,58 @@ SECRET=replace-me
       await fs.rmdir(tmpDir);
     });
 
-    it("should handle non-existent files gracefully", async () => {
+    it("should return error state for non-existent files", async () => {
       const result = await service.scanFile("/non/existent/file.ts");
 
       expect(result.hasSecrets).toBe(false);
       expect(result.count).toBe(0);
+      expect(result.scannedSuccessfully).toBe(false);
+      expect(result.scanError).toBeDefined();
+      expect(result.scanError).toContain("ENOENT");
+    });
+
+    it("should return scannedSuccessfully true for successful scans", async () => {
+      const fs = await import("fs/promises");
+      const path = await import("path");
+      const os = await import("os");
+
+      const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "secret-test-"));
+      const testFile = path.join(tmpDir, "clean.ts");
+
+      await fs.writeFile(testFile, 'const message = "Hello World";\n');
+
+      const result = await service.scanFile(testFile);
+
+      expect(result.scannedSuccessfully).toBe(true);
+      expect(result.scanError).toBeUndefined();
+
+      // Cleanup
+      await fs.unlink(testFile);
+      await fs.rmdir(tmpDir);
+    });
+
+    it("should return error state for unreadable files", async () => {
+      const fs = await import("fs/promises");
+      const path = await import("path");
+      const os = await import("os");
+
+      const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "secret-test-"));
+      const testFile = path.join(tmpDir, "unreadable.ts");
+
+      await fs.writeFile(testFile, 'const key = "AKIAREALKEY123456789";\n');
+      // Remove read permissions
+      await fs.chmod(testFile, 0o000);
+
+      const result = await service.scanFile(testFile);
+
+      expect(result.scannedSuccessfully).toBe(false);
+      expect(result.scanError).toBeDefined();
+      expect(result.hasSecrets).toBe(false); // Not "clean", just unscanned
+
+      // Cleanup - restore permissions first
+      await fs.chmod(testFile, 0o644);
+      await fs.unlink(testFile);
+      await fs.rmdir(tmpDir);
     });
   });
 
@@ -433,6 +480,7 @@ SECRET=replace-me
           filePath: "file1.ts",
           hasSecrets: true,
           count: 2,
+          scannedSuccessfully: true,
           matches: [
             {
               patternName: "AWS Access Key",
@@ -454,6 +502,7 @@ SECRET=replace-me
           filePath: "file2.ts",
           hasSecrets: false,
           count: 0,
+          scannedSuccessfully: true,
           matches: [],
         },
       ];
@@ -463,10 +512,54 @@ SECRET=replace-me
       expect(summary.totalFiles).toBe(2);
       expect(summary.filesWithSecrets).toBe(1);
       expect(summary.totalSecrets).toBe(2);
+      expect(summary.filesWithErrors).toBe(0);
       expect(summary.bySeverity.critical).toBe(1);
       expect(summary.bySeverity.high).toBe(1);
       expect(summary.bySeverity.medium).toBe(0);
     });
+
+    it("should count files with scan errors", () => {
+      const results = [
+        {
+          filePath: "file1.ts",
+          hasSecrets: true,
+          count: 1,
+          scannedSuccessfully: true,
+          matches: [
+            {
+              patternName: "AWS Access Key",
+              match: "AKIA...",
+              line: 1,
+              column: 1,
+              severity: "critical" as const,
+            },
+          ],
+        },
+        {
+          filePath: "file2.ts",
+          hasSecrets: false,
+          count: 0,
+          scannedSuccessfully: false,
+          scanError: "ENOENT: no such file or directory",
+          matches: [],
+        },
+        {
+          filePath: "file3.ts",
+          hasSecrets: false,
+          count: 0,
+          scannedSuccessfully: false,
+          scanError: "EACCES: permission denied",
+          matches: [],
+        },
+      ];
+
+      const summary = service.getScanSummary(results);
+
+      expect(summary.totalFiles).toBe(3);
+      expect(summary.filesWithSecrets).toBe(1);
+      expect(summary.filesWithErrors).toBe(2);
+      expect(summary.totalSecrets).toBe(1);
+    });
   });
 
   describe("SecretsDetectedError", () => {
@@ -476,6 +569,7 @@ SECRET=replace-me
           filePath: "test.ts",
           hasSecrets: true,
           count: 1,
+          scannedSuccessfully: true,
           matches: [
             {
               patternName: "AWS Access Key",
@@ -500,6 +594,7 @@ SECRET=replace-me
           filePath: "config.ts",
           hasSecrets: true,
           count: 1,
+          scannedSuccessfully: true,
           matches: [
             {
               patternName: "API Key",
@@ -521,6 +616,44 @@ SECRET=replace-me
       expect(detailed).toContain("Line 5:15");
       expect(detailed).toContain("API Key");
     });
+
+    it("should include scan errors in detailed message", () => {
+      const results = [
+        {
+          filePath: "config.ts",
+          hasSecrets: true,
+          count: 1,
+          scannedSuccessfully: true,
+          matches: [
+            {
+              patternName: "API Key",
+              match: "abc123",
+              line: 5,
+              column: 15,
+              severity: "high" as const,
+              context: 'const apiKey = "abc123"',
+            },
+          ],
+        },
+        {
+          filePath: "unreadable.ts",
+          hasSecrets: false,
+          count: 0,
+          scannedSuccessfully: false,
+          scanError: "EACCES: permission denied",
+          matches: [],
+        },
+      ];
+
+      const error = new SecretsDetectedError(results);
+      const detailed = error.getDetailedMessage();
+
+      expect(detailed).toContain("SECRETS DETECTED");
+      expect(detailed).toContain("config.ts");
+      expect(detailed).toContain("could not be scanned");
+      expect(detailed).toContain("unreadable.ts");
+      expect(detailed).toContain("EACCES: permission denied");
+    });
   });
 
   describe("Custom Patterns", () => {