WIP: Agent/AgentState — 36 errors remaining, all .lock() → .state.lock() or .context.lock()

Bulk replaced Arc<Mutex<Agent>> with Arc<Agent> across all files.
Fixed control.rs, memory.rs tool handlers. Fixed oneshot Backend.
Remaining errors are all agent.lock() → agent.state.lock() or
agent.context.lock() in mind/, user/, and a few in mod.rs.

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

src/user/chat.rs

@@ -98,7 +98,7 @@ fn dispatch_command(input: &str) -> Option<SlashCommand> {
 
 /// Switch model — used by both /model command and tool-initiated switches.
 pub async fn cmd_switch_model(
-    agent: &std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>,
+    agent: &std::sync::Arc<crate::agent::Agent>,
     name: &str,
 ) {
     let resolved = {
@@ -129,7 +129,7 @@ pub async fn cmd_switch_model(
     }
 }
 
-fn notify_help(agent: &std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>) {
+fn notify_help(agent: &std::sync::Arc<crate::agent::Agent>) {
     if let Ok(mut ag) = agent.try_lock() {
         let mut help = String::new();
         for cmd in &commands() {
@@ -380,14 +380,14 @@ pub(crate) struct InteractScreen {
     last_entries: Vec<AstNode>,
     pending_display_count: usize,
     /// Reference to agent for state sync
-    agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>,
+    agent: std::sync::Arc<crate::agent::Agent>,
     shared_mind: std::sync::Arc<crate::mind::SharedMindState>,
     mind_tx: tokio::sync::mpsc::UnboundedSender<crate::mind::MindCommand>,
 }
 
 impl InteractScreen {
     pub fn new(
-        agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>,
+        agent: std::sync::Arc<crate::agent::Agent>,
         shared_mind: std::sync::Arc<crate::mind::SharedMindState>,
         mind_tx: tokio::sync::mpsc::UnboundedSender<crate::mind::MindCommand>,
     ) -> Self {

src/user/context.rs

@@ -10,12 +10,12 @@ use super::widgets::{SectionTree, SectionView, section_to_view, pane_block, rend
 use crate::agent::context::{AstNode, NodeBody, Ast};
 
 pub(crate) struct ConsciousScreen {
-    agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>,
+    agent: std::sync::Arc<crate::agent::Agent>,
     tree: SectionTree,
 }
 
 impl ConsciousScreen {
-    pub fn new(agent: std::sync::Arc<tokio::sync::Mutex<crate::agent::Agent>>) -> Self {
+    pub fn new(agent: std::sync::Arc<crate::agent::Agent>) -> Self {
         Self { agent, tree: SectionTree::new() }
     }