cli: convert simple commands to use memory_rpc

Commands now forward to daemon (or fallback to local store):
- query → memory_query
- journal tail → journal_tail
- graph link-set → memory_link_set
- graph link-add → memory_link_add
- weight-set → memory_weight_set
- node rename → memory_rename

Removes ~50 lines of duplicated store access code.

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

src/cli/graph.rs

@@ -153,35 +153,23 @@ pub fn cmd_link(key: &[String]) -> Result<(), String> {
         &format!("neighbors('{}') | select strength,clustering_coefficient", resolved))
 }
 
-pub fn cmd_link_add(source: &str, target: &str, reason: &[String]) -> Result<(), String> {
+pub fn cmd_link_add(source: &str, target: &str, _reason: &[String]) -> Result<(), String> {
     super::check_dry_run();
-    let mut store = store::Store::load()?;
-    let source = store.resolve_key(source)?;
-    let target = store.resolve_key(target)?;
-    let reason = reason.join(" ");
-
-    match store.add_link(&source, &target, "manual") {
-        Ok(strength) => {
-            store.save()?;
-            println!("Linked: {} → {} (strength={:.2}, {})", source, target, strength, reason);
-        }
-        Err(msg) if msg.contains("already exists") => {
-            println!("Link already exists: {} ↔ {}", source, target);
-        }
-        Err(e) => return Err(e),
-    }
+    let result = crate::mcp_server::memory_rpc(
+        "memory_link_add",
+        serde_json::json!({"source": source, "target": target}),
+    ).map_err(|e| e.to_string())?;
+    println!("{}", result);
     Ok(())
 }
 
 pub fn cmd_link_set(source: &str, target: &str, strength: f32) -> Result<(), String> {
     super::check_dry_run();
-    let mut store = store::Store::load()?;
-    let source = store.resolve_key(source)?;
-    let target = store.resolve_key(target)?;
-
-    let old = store.set_link_strength(&source, &target, strength)?;
-    println!("Set: {} ↔ {} strength {:.2} → {:.2}", source, target, old, strength);
-    store.save()?;
+    let result = crate::mcp_server::memory_rpc(
+        "memory_link_set",
+        serde_json::json!({"source": source, "target": target, "strength": strength}),
+    ).map_err(|e| e.to_string())?;
+    println!("{}", result);
     Ok(())
 }