tighten module interfaces: explicit re-exports, private helpers, inline dedup

- Replace `pub use types::*` in store/mod.rs with explicit re-export list
- Make transcript_dedup_key private in agents/enrich.rs (only used internally)
- Inline duplicated projects_dir() helper in agents/knowledge.rs and daemon.rs

poc-memory/src/agents/daemon.rs

@@ -34,10 +34,6 @@ fn log_path() -> PathBuf {
     crate::config::get().data_dir.join(log_file())
 }
 
-fn projects_dir() -> PathBuf {
-    crate::config::get().projects_dir.clone()
-}
-
 // --- Logging ---
 
 const LOG_MAX_BYTES: u64 = 1_000_000; // 1MB, then truncate to last half
@@ -181,7 +177,7 @@ fn job_daily_check(ctx: &ExecutionContext) -> Result<(), TaskError> {
 const MIN_SESSION_BYTES: u64 = 100_000;
 
 fn find_stale_sessions() -> Vec<PathBuf> {
-    let projects = projects_dir();
+    let projects = crate::config::get().projects_dir.clone();
     if !projects.exists() {
         return Vec::new();
     }