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

crates/mem-cli/src/rbac/policy_provider.rs

@@ -8,11 +8,12 @@
 
 use anyhow::Result;
 use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::sync::Arc;
 use tokio::sync::RwLock;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct AccessPolicy {
     pub access_level: String,      // "public" | "group" | "private"
     pub owner_group: String,