fix(tui): perbaiki potensi terpotongnya baris token di widget Usage sidebar

Baris pertama widget Usage sebelumnya bisa melebihi lebar kolom sidebar
(30 kolom) pada sesi dengan jumlah token besar, menyebabkan teks
terpotong diam-diam tanpa wrap. Sekarang dipecah jadi beberapa baris
pendek yang aman di lebar berapa pun yang realistis.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/view/sidebar.rs

@@ -58,11 +58,18 @@ fn draw_tasks_widget(frame: &mut Frame, area: Rect, state: &crate::app::state::r
     frame.render_widget(paragraph, area);
 }
 
-/// Compact Usage widget: main/self-learning token split, API call count,
-/// and session clock. Always fits (the summary is a fixed handful of
-/// lines), so there is no overflow hint — the `Overlay::Usage` "expand"
-/// view adds edit/review/lesson activity counters on top of this same
-/// summary rather than showing more of a truncated list.
+/// Compact Usage widget: total tokens, main/self-learning token split,
+/// API call count, and session clock. Always fits (the summary is a
+/// fixed handful of lines), so there is no overflow hint — the
+/// `Overlay::Usage` "expand" view adds edit/review/lesson activity
+/// counters on top of this same summary rather than showing more of a
+/// truncated list.
+///
+/// Each number gets its own short line rather than being crammed onto
+/// one — the sidebar column is only ~28 usable characters wide after
+/// borders, and a single `"{total} tok ({main} main / {learn} learn)"`
+/// line silently clips (no `.wrap()` on this `Paragraph`) once token
+/// counts reach 5-6 digits, which is routine for an agent session.
 fn draw_usage_widget(frame: &mut Frame, area: Rect, state: &crate::app::state::rest::AppStateRest) {
     let block = Block::default()
         .title(Span::styled(" Usage ", Style::default().fg(Theme::INFO).add_modifier(Modifier::BOLD)))
@@ -74,9 +81,17 @@ fn draw_usage_widget(frame: &mut Frame, area: Rect, state: &crate::app::state::r
         let summary = compute_usage_summary(&rt.usage, rt.session_start, now_ms);
         vec![
             Line::from(Span::styled(
-                format!(" {} tok ({} main / {} learn)", summary.total_tokens, summary.main_tokens, summary.self_learning_tokens),
+                format!(" {} tok total", summary.total_tokens),
                 Style::default().fg(Theme::TEXT).add_modifier(Modifier::BOLD),
             )),
+            Line::from(Span::styled(
+                format!(" main: {} tok", summary.main_tokens),
+                Style::default().fg(Theme::TEXT_DIM),
+            )),
+            Line::from(Span::styled(
+                format!(" learn: {} tok", summary.self_learning_tokens),
+                Style::default().fg(Theme::TEXT_DIM),
+            )),
             Line::from(Span::styled(
                 format!(" {} API calls", summary.api_calls),
                 Style::default().fg(Theme::TEXT_DIM),