feat: Implement lesson generation feature and update status display

- Added functionality to generate lessons based on code reviews, including prompts and instructions for the reviewer.
- Updated the `.gitignore` to exclude lesson documentation files.
- Removed the `/lesson` command from the help menu and command parsing.
- Enhanced the status bar to display a message when a lesson is being generated.
- Introduced a new `lesson_running` state to track lesson generation progress.
- Updated various components to handle the new lesson generation workflow, including subagent events and token usage tracking.

src/app/state/misc.rs

@@ -79,7 +79,6 @@ const COMMANDS: &[&str] = &[
     "/help",
     "/quit",
     "/clear",
-    "/lesson",
     "/login",
     "/login zen",
     "/login openai",
@@ -291,6 +290,7 @@ pub struct MiscState {
     pub api_context_length: Option<u32>,
     pub tick_count: u64,
     pub todo_content: String,
+    pub lesson_running: bool,
 }
 
 impl MiscState {
@@ -309,6 +309,7 @@ impl MiscState {
             api_context_length: None,
             tick_count: 0,
             todo_content: String::new(),
+            lesson_running: false,
         }
     }
 

src/app/state/runtime.rs

@@ -108,6 +108,16 @@ pub enum TurnEvent {
         tokens_in: u64,
         tokens_out: u64,
     },
+    /// Token usage from a subagent (review, test-gen, arch-review, etc.)
+    /// routed to `UsageStats::review_tokens` so the Usage panel can split
+    /// "main" tokens from "self-learning" tokens. Same shape as `Usage` but
+    /// kept as a distinct variant so future subagent-specific metadata
+    /// (origin tag, subagent name) can be attached without breaking the
+    /// main-agent path.
+    ReviewUsage {
+        tokens_in: u64,
+        tokens_out: u64,
+    },
     Compacted(Vec<crate::dto::chat::message::ChatMessage>),
     Error(String),
     Done,