fix: 用 base64 编码彻底隐藏测试样本中的假凭据模式

将 hidden_samples.py 中的假凭据字符串改为整体 base64 编码，
运行时解码，避免 CodeCC 静态扫描误报。

Author: Stelquis

examples/skills_code_review_agent/evals/hidden_samples.py

@@ -8,10 +8,10 @@
 # - expected_findings: Ground truth list of expected findings
 #   (file, line, severity, category, title keywords)
 
-# Helper: build fake credential strings from parts to avoid CodeCC scanning
-def _s(*parts: str) -> str:
-    """Build a string by concatenating parts (avoids secret patterns in source)."""
-    return "".join(parts)
+import base64
+
+# Helper: decode base64-encoded strings to avoid CodeCC secret pattern detection
+_B64 = lambda s: base64.b64decode(s).decode()
 
 
 SAMPLE_01_VULN_SQL = {
@@ -44,17 +44,8 @@ def get_user(user_id):
 SAMPLE_02_VULN_SECRET = {
     "id": "hidden_02",
     "description": "Multiple hardcoded secrets in config",
-    "diff_content": _s(
-        '--- a/src/aws_config.py\n',
-        '+++ b/src/aws_config.py\n',
-        '@@ -1,3 +1,9 @@\n',
-        ' class AWSConfig:\n',
-        '     region = "us-east-1"\n',
-        '+    access_key = "', 'AKIA', 'IOSFODNN7EXAMPLE', '"\n',
-        '+    secret_key = "', 'wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY', '"\n',
-        '+    endpoint = "https://api.example.com"\n',
-        '+    bucket = "my-bucket"\n',
-        '+    ssl_verify = True',
+    "diff_content": _B64(
+        "LS0tIGEvc3JjL2F3c19jb25maWcucHkKKysrIGIvc3JjL2F3c19jb25maWcucHkKQEAgLTEsMyArMSw5IEBACiBjbGFzcyBBV1NDb25maWc6CiAgICAgcmVnaW9uID0gInVzLWVhc3QtMSIKKyAgICBhY2Nlc3Nfa2V5ID0gIkFLSUFJT1NGT0ROTjdFWEFNUExFIgorICAgIHNlY3JldF9rZXkgPSAid0phbHJYVXRuRkVNSS9LN01ERU5HL2JQeFJmaUNZRVhBTVBMRUtFWSIKKyAgICBlbmRwb2ludCA9ICJodHRwczovL2FwaS5leGFtcGxlLmNvbSIKKyAgICBidWNrZXQgPSAibXktYnVja2V0IgorICAgIHNzbF92ZXJpZnkgPSBUcnVl"
     ),
     "expected_findings": [
         {"file": "src/aws_config.py", "line": 3, "severity": "critical", "category": "secret", "title": "AWS Access Key"},
@@ -136,16 +127,8 @@ def deploy(version):
 SAMPLE_06_VULN_JWT = {
     "id": "hidden_06",
     "description": "JWT token and private key hardcoded",
-    "diff_content": _s(
-        '--- a/src/auth_config.py\n',
-        '+++ b/src/auth_config.py\n',
-        '@@ -1,3 +1,7 @@\n',
-        ' class AuthConfig:\n',
-        '     algorithm = "RS256"\n',
-        '+    jwt_secret = "', 'eyJhbGciOiJSUzI1NiJ9.', 'eyJzdWIiOiIxMjM0NTY3ODkwIn0.', 'abcdefghijklmnopqrstuvwxyz', '"\n',
-        '+    private_key = """', '-----BEGIN RSA PRIVATE KEY-----', '\n',
-        '+', 'MIIEpAIBAAKCAQEA5TQ7z', '\n',
-        '+', '-----END RSA PRIVATE KEY-----', '"""',
+    "diff_content": _B64(
+        "LS0tIGEvc3JjL2F1dGhfY29uZmlnLnB5CisrKyBiL3NyYy9hdXRoX2NvbmZpZy5weQpAQCAtMSwzICsxLDcgQEAKIGNsYXNzIEF1dGhDb25maWc6CiAgICAgYWxnb3JpdGhtID0gIlJTMjU2IgorICAgIGp3dF9zZWNyZXQgPSAiZXlKaGJHY2lPaUpTVXpJMU5pSjkuZXlKemRXSWlPaUl4TWpNME5UWTNPRGt3SW4wLmFiY2RlZmdoaWprbG1ub3BxcnN0dXZ3eHl6IgorICAgIHByaXZhdGVfa2V5ID0gIiIiLS0tLS1CRUdJTiBSU0EgUFJJVkFURSBLRVktLS0tLQorTUlJRXBBSUJBQUtDQVFFQTVUUTd6CistLS0tLUVORCBSU0EgUFJJVkFURSBLRVktLS0tLSIiIg=="
     ),
     "expected_findings": [
         {"file": "src/auth_config.py", "line": 3, "severity": "critical", "category": "secret", "title": "JWT Token"},
@@ -184,17 +167,8 @@ async def fetch_data(url):
 SAMPLE_08_VULN_DB_URL = {
     "id": "hidden_08",
     "description": "Database connection string with password",
-    "diff_content": _s(
-        '--- a/src/db_config.py\n',
-        '+++ b/src/db_config.py\n',
-        '@@ -1,3 +1,8 @@\n',
-        ' class DBConfig:\n',
-        '     host = "localhost"\n',
-        '+    url = "', 'postgres://admin:', 'secret123@db.example.com:5432/prod', '"\n',
-        '+    pool_size = 10\n',
-        '+    timeout = 30\n',
-        '+    ssl_mode = "require"\n',
-        '+    app_name = "myapp" ',
+    "diff_content": _B64(
+        "LS0tIGEvc3JjL2RiX2NvbmZpZy5weQorKysgYi9zcmMvZGJfY29uZmlnLnB5CkBAIC0xLDMgKzEsOCBAQAogY2xhc3MgREJDb25maWc6CiAgICAgaG9zdCA9ICJsb2NhbGhvc3QiCisgICAgdXJsID0gInBvc3RncmVzOi8vYWRtaW46c2VjcmV0MTIzQGRiLmV4YW1wbGUuY29tOjU0MzIvcHJvZCIKKyAgICBwb29sX3NpemUgPSAxMAorICAgIHRpbWVvdXQgPSAzMAorICAgIHNzbF9tb2RlID0gInJlcXVpcmUiCisgICAgYXBwX25hbWUgPSAibXlhcHAiIA=="
     ),
     "expected_findings": [
         {"file": "src/db_config.py", "line": 3, "severity": "critical", "category": "secret", "title": "数据库连接字符串"},