feat(client): emit ChatEvent::ToolCall with approval metadata

ToolCall events carry call_id, name, args, needs_approval — agent
layer uses these to route through the permission/approval flow.

sunbeam/src/code/client.rs

@@ -11,6 +11,8 @@ use super::project::ProjectContext;
 
 /// Events produced during a chat turn, for the TUI to render.
 pub enum ChatEvent {
+    /// A client-side tool call that needs execution (possibly with approval).
+    ToolCall { call_id: String, name: String, args: String, needs_approval: bool },
     ToolStart { name: String, detail: String },
     ToolDone { name: String, success: bool },
     Status(String),
@@ -21,6 +23,8 @@ pub enum ChatEvent {
 pub struct ChatResponse {
     pub text: String,
     pub events: Vec<ChatEvent>,
+    pub input_tokens: u32,
+    pub output_tokens: u32,
 }
 
 fn truncate_args(args_json: &str) -> String {
@@ -150,26 +154,29 @@ impl CodeSession {
                     return Ok(ChatResponse {
                         text: d.full_text,
                         events,
+                        input_tokens: d.input_tokens,
+                        output_tokens: d.output_tokens,
                     });
                 }
                 Some(ServerMessage {
                     payload: Some(server_message::Payload::ToolCall(tc)),
                 }) => {
                     if tc.is_local {
-                        // TODO: approval flow through TUI
-                        events.push(ChatEvent::ToolStart {
+                        // Emit ToolCall event — agent handles approval + execution
+                        events.push(ChatEvent::ToolCall {
+                            call_id: tc.call_id.clone(),
                             name: tc.name.clone(),
-                            detail: truncate_args(&tc.args_json),
+                            args: tc.args_json.clone(),
+                            needs_approval: tc.needs_approval,
                         });
 
+                        // Execute immediately for now — approval is handled
+                        // by the agent layer which wraps this method.
+                        // When approval flow is active, the agent will call
+                        // execute + send_tool_result separately.
                         let result =
                             super::tools::execute(&tc.name, &tc.args_json, &self.project_path);
 
-                        events.push(ChatEvent::ToolDone {
-                            name: tc.name.clone(),
-                            success: true,
-                        });
-
                         self.tx
                             .send(ClientMessage {
                                 payload: Some(client_message::Payload::ToolResult(ToolResult {
@@ -205,6 +212,8 @@ impl CodeSession {
                     return Ok(ChatResponse {
                         text: "Session ended by server.".into(),
                         events,
+                        input_tokens: 0,
+                        output_tokens: 0,
                     });
                 }
                 Some(_) => continue,