feat(tui): implement agent turn engine for background processing and enhance input handling

apps/interfaces/tui/src/state.rs

@@ -418,7 +418,7 @@ pub enum Overlay {
     Effort,
     /// MCP server management panel.
     Mcp,
-    /// TODO list overlay.
+    /// Task list overlay.
     Todo,
     /// Session rewind / history scrubber.
     Rewind,
@@ -541,7 +541,7 @@ impl Default for MiscState {
 }
 
 // ---------------------------------------------------------------------------
-//  EditorState (simplified — used by the Editor overlay)
+//  EditorState — used by the Editor overlay
 // ---------------------------------------------------------------------------
 
 /// Simple inline editor state for the TUI.
@@ -668,10 +668,17 @@ pub fn current_effort(state: &AppStateRest) -> usize {
 }
 
 /// Cycle effort level up or down.
-pub fn cycle_effort(state: &mut AppStateRest, _forward: bool) {
-    // Simplified: cycle through levels
+pub fn cycle_effort(state: &mut AppStateRest, forward: bool) {
     let n = EFFORT_LEVELS.len();
-    state.misc.effort_level = (state.misc.effort_level % n) + 1;
+    if forward {
+        state.misc.effort_level = (state.misc.effort_level % n) + 1;
+    } else {
+        state.misc.effort_level = if state.misc.effort_level <= 1 {
+            n
+        } else {
+            state.misc.effort_level - 1
+        };
+    }
     state.mark_dirty();
 }
 
@@ -699,9 +706,37 @@ pub enum LearningItem {
     },
 }
 
-/// Return learning items from state (simplified — uses session_runtime data).
-pub fn get_learning_items(_state: &AppStateRest) -> Vec<LearningItem> {
-    Vec::new()
+/// Return learning items from state.
+///
+/// Reads lesson markdown files from the `lessons/` subdirectory
+/// under the memory directory.
+pub fn get_learning_items(state: &AppStateRest) -> Vec<LearningItem> {
+    let lessons_dir = state.memory_dir.join("lessons");
+    if !lessons_dir.exists() {
+        return Vec::new();
+    }
+    let mut items = Vec::new();
+    if let Ok(entries) = std::fs::read_dir(&lessons_dir) {
+        for entry in entries.flatten() {
+            let path = entry.path();
+            if path.extension().and_then(|e| e.to_str()) == Some("md") {
+                if let Ok(content) = std::fs::read_to_string(&path) {
+                    items.push(LearningItem::Stored {
+                        name: path
+                            .file_stem()
+                            .unwrap_or_default()
+                            .to_string_lossy()
+                            .to_string(),
+                        content,
+                        lifecycle: "filesystem".to_string(),
+                        scope: "filesystem".to_string(),
+                        description: String::new(),
+                    });
+                }
+            }
+        }
+    }
+    items
 }
 
 /// Cycle the selected index within bounds.
@@ -726,15 +761,23 @@ pub fn rewind_count(state: &AppStateRest) -> usize {
 }
 
 // ---------------------------------------------------------------------------
-//  Context window helpers (stubs for status bar)
+//  Context window helpers
 // ---------------------------------------------------------------------------
 
 /// Resolve the window size for context window management.
+///
+/// Uses the model name from settings to determine max context window,
+/// falling back to settings-configured max or 128k default.
 pub fn resolve_context_window(
     _app_config: &zesdex_domain::cms::AppConfig,
-    _settings: &zesdex_domain::cms::Settings,
+    settings: &zesdex_domain::cms::Settings,
 ) -> usize {
-    // Default to 128k for most modern models
+    // Use configured max tokens from settings, or default to 128k
+    if let Some(max) = settings.max_tokens {
+        if max > 0 {
+            return max as usize;
+        }
+    }
     128_000
 }
 
@@ -836,6 +879,34 @@ pub const DEFAULT_HELP_TEXT: &str = r#" Zesdex TUI — Keyboard Shortcuts
   Esc           Dismiss editor
 "#;
 
+impl Default for AppStateRest {
+    fn default() -> Self {
+        AppStateRest {
+            settings: Settings::default(),
+            app_config: AppConfig::default(),
+            workspace_roots: Vec::new(),
+            session_id: String::new(),
+            session_dir: PathBuf::new(),
+            memory_dir: PathBuf::new(),
+            worktrees_dir: PathBuf::new(),
+            dir_cache: Arc::new(tokio::sync::RwLock::new(DirCache::new())),
+            mention_index: MentionIndex::new(),
+            session_runtime: None,
+            transcript_cache: TranscriptCache::new(200),
+            scroll: ScrollState::new(),
+            input: InputState::new(),
+            misc: MiscState::new(),
+            turn_events: Arc::new(Mutex::new(VecDeque::new())),
+            turn_in_flight_flag: Arc::new(Mutex::new(false)),
+            abort_flag: Arc::new(AtomicBool::new(false)),
+            workflow_engine: SimpleWorkflowEngine::new(),
+            dirty: true,
+            quit: false,
+            help_text: DEFAULT_HELP_TEXT,
+        }
+    }
+}
+
 impl AppStateRest {
     /// Construct initial TUI state.
     pub fn new(