Add tool use to the orchestrator (#4)

Add tool use without sandboxing.

Currently available tools are list dir, read file, write file and exec bash.

Reviewed-on: #4
Co-authored-by: Drew Galbraith <drew@tiramisu.one>
Co-committed-by: Drew Galbraith <drew@tiramisu.one>

src/tui/input.rs

@@ -13,6 +13,8 @@ pub(super) enum LoopControl {
     Quit,
     /// The user ran `:clear`; wipe the conversation.
     ClearHistory,
+    /// The user responded to a tool approval prompt.
+    ToolApproval { tool_use_id: String, approved: bool },
 }
 
 /// Map a key event to a [`LoopControl`] signal, mutating `state` as a side-effect.
@@ -23,6 +25,29 @@ pub(super) fn handle_key(key: Option<KeyEvent>, state: &mut AppState) -> Option<
     let key = key?;
     // Clear any transient status error on the next keypress.
     state.status_error = None;
+
+    // If a tool approval is pending, intercept y/n before normal key handling.
+    if let Some(approval) = &state.pending_approval {
+        let tool_use_id = approval.tool_use_id.clone();
+        match key.code {
+            KeyCode::Char('y') | KeyCode::Char('Y') => {
+                state.pending_approval = None;
+                return Some(LoopControl::ToolApproval {
+                    tool_use_id,
+                    approved: true,
+                });
+            }
+            KeyCode::Char('n') | KeyCode::Char('N') => {
+                state.pending_approval = None;
+                return Some(LoopControl::ToolApproval {
+                    tool_use_id,
+                    approved: false,
+                });
+            }
+            _ => return None, // ignore other keys while approval pending
+        }
+    }
+
     // Ctrl+C quits from any mode.
     if key.modifiers.contains(KeyModifiers::CONTROL) && key.code == KeyCode::Char('c') {
         return Some(LoopControl::Quit);