Convert store and CLI to anyhow::Result for cleaner error handling

Replace Result<_, String> with anyhow::Result throughout:
- hippocampus/store module (persist, ops, types, view, mod)
- CLI modules (admin, agent, graph, journal, node)
- Run trait in main.rs

Use .context() and .with_context() instead of .map_err(|e| format!(...))
patterns. Add bail!() for early error returns.

Add access_local() helper in hippocampus/mod.rs that returns
Result<Arc<Mutex<Store>>> for direct local store access.

Fix store access patterns to properly lock Arc<Mutex<Store>> before
accessing fields in mind/unconscious.rs, mind/mod.rs, subconscious/learn.rs,
and hippocampus/memory.rs.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/mind/unconscious.rs

@@ -12,6 +12,7 @@ use futures::FutureExt;
 use crate::agent::oneshot::{AutoAgent, AutoStep, RunStats};
 use crate::agent::tools;
 use crate::subconscious::defs;
+use crate::hippocampus::access_local;
 
 fn config_path() -> std::path::PathBuf {
     dirs::home_dir().unwrap_or_default()
@@ -254,12 +255,9 @@ pub async fn prepare_spawn(name: &str, mut auto: AutoAgent) -> Result<SpawnResul
     };
 
     // Run query and resolve placeholders
-    let mut store = match crate::store::Store::load() {
+    let store_arc = match access_local() {
         Ok(s) => s,
-        Err(e) => {
-            dbglog!("[unconscious] store load failed: {}", e);
-            return Err(auto);
-        }
+        Err(_) => return Err(auto),
     };
 
     let exclude: std::collections::HashSet<String> = std::collections::HashSet::new();
@@ -274,6 +272,7 @@ pub async fn prepare_spawn(name: &str, mut auto: AutoAgent) -> Result<SpawnResul
     };
 
     if !batch.node_keys.is_empty() {
+        let mut store = store_arc.lock().await;
         store.record_agent_visits(&batch.node_keys, name).ok();
     }