fix: add test fixtures integration tests, fix serde derives

All tests now passing:
- 5 wiki_link tests (parsing, path resolution, graph traversal)
- 5 scoring_pipeline tests (TF-IDF, semantic, metadata boosting)
- 8 rbac tests (access level, role, permission checks)
- 14 fixtures tests (builders, mocks)

Total: 32 passing unit/integration tests for Phase 1, 2, 7

tests/it_fixtures.rs

@@ -0,0 +1,64 @@
+mod fixtures;
+
+use fixtures::builders::{OidcClaimsBuilder, AccessPolicyBuilder};
+use fixtures::mocks::{MockPolicyProvider, MockAuditLogger, ConstantScorer};
+
+#[test]
+fn test_oidc_claims_builder() {
+    let claims = OidcClaimsBuilder::new("charlie")
+        .group("platform-team")
+        .group("devops-team")
+        .permission("memory:read")
+        .build();
+
+    assert_eq!(claims.sub, "charlie");
+    assert_eq!(claims.groups.len(), 2);
+    assert!(claims.permissions.contains(&"memory:read".to_string()));
+}
+
+#[test]
+fn test_access_policy_builder_public() {
+    let policy = AccessPolicyBuilder::public().build();
+
+    assert_eq!(policy.access_level, "public");
+    assert!(policy.owner_group.is_empty());
+}
+
+#[test]
+fn test_access_policy_builder_private() {
+    let policy = AccessPolicyBuilder::public()
+        .private("ml-team")
+        .build();
+
+    assert_eq!(policy.access_level, "private");
+    assert_eq!(policy.owner_group, "ml-team");
+}
+
+#[tokio::test]
+async fn test_mock_policy_provider() {
+    let provider = MockPolicyProvider::new();
+    let policy = AccessPolicyBuilder::public()
+        .group(vec!["platform-team", "devops-team"])
+        .build();
+
+    let provider = provider.with_policy("project", "poimen", policy.clone());
+    let retrieved = provider.get_policy("project", "poimen").await.unwrap();
+
+    assert_eq!(retrieved.access_level, policy.access_level);
+}
+
+#[test]
+fn test_mock_audit_logger() {
+    let logger = MockAuditLogger::new();
+    logger.log_decision_sync("charlie:allow".to_string());
+
+    let decisions = logger.decisions();
+    assert_eq!(decisions.len(), 1);
+    assert!(decisions[0].contains("charlie"));
+}
+
+#[test]
+fn test_constant_scorer() {
+    let scorer = ConstantScorer::new(0.75);
+    assert_eq!(scorer.name(), "constant-mock");
+}