feat: add lesson export and import functionality

- Implemented `LessonExport` and `LessonImport` actions in the action module.
- Added corresponding command parsing for lesson export and import.
- Created functions to handle lesson export and import in the memory module.
- Updated state management to reflect changes after lesson operations.
- Introduced deferred operations for handling asynchronous tasks in the event loop.
- Enhanced the tool execution context to include graduated checks for file operations.
- Added OAuth support with PKCE for secure authorization flows.
- Implemented a loopback server for handling OAuth redirects.
- Refactored various modules to improve code organization and maintainability.

src/app/runtime/commands.rs

@@ -0,0 +1,53 @@
+use crate::controller::command::Command;
+use crate::app::runtime::actions::Action;
+use crate::app::state::types::Overlay;
+
+pub fn apply_command(command: Command) -> Vec<Action> {
+    match command {
+        Command::Help => {
+            vec![Action::OpenOverlay(Overlay::Help)]
+        }
+        Command::Quit => {
+            vec![Action::QuitConfirm]
+        }
+        Command::Resume => {
+            vec![Action::CloseOverlay]
+        }
+        Command::LessonCreate(text) => {
+            vec![Action::SystemNote {
+                kind: "lesson".to_string(),
+                message: format!("/lesson {}", text),
+            }]
+        }
+        Command::LessonExport(path) => {
+            vec![Action::LessonExport { path }]
+        }
+        Command::LessonImport(path) => {
+            vec![Action::LessonImport { path }]
+        }
+        Command::LessonList => {
+            vec![Action::OpenOverlay(Overlay::Learning)]
+        }
+        Command::Mode(mode) => {
+            vec![Action::SwitchMode(mode)]
+        }
+        Command::Clear => {
+            vec![Action::SystemNote {
+                kind: "clear".to_string(),
+                message: "transcript cleared".to_string(),
+            }]
+        }
+        Command::Save => {
+            vec![Action::SystemNote {
+                kind: "save".to_string(),
+                message: "session saved".to_string(),
+            }]
+        }
+        Command::Unknown(cmd) => {
+            vec![Action::SystemNote {
+                kind: "error".to_string(),
+                message: format!("unknown command: {}", cmd),
+            }]
+        }
+    }
+}