fix(bubble): codex accent → white, percent rides fill edge

Codex stripe is white in dark mode and charcoal (#2A2A2A) in light mode
— a pure white would vanish into the light-mode #F3F3F3 background, so
the light-mode variant keeps the same monochrome-vs-orange identity
without disappearing. Mirrored into the expanded panel.

Inline percent now anchors to the fill's trailing edge instead of the
bar's far-right. Two modes:

- Fill is wide enough (fill_w >= text_w + 2*inset): right-align the
  percent *inside* the fill at its trailing edge. Text sits on the
  fill colour.
- Fill is too narrow: left-align the percent just past the fill on
  the track. Text follows the fill's edge.

Previously the percent was always right-aligned to bar_right - inset,
which detached it from the fill at low percentages — e.g. at 42% the
"42%" floated near the bar's right end while the fill stopped at
~42% of bar width. Now the percent rides the fill so the visual
relationship between number and bar length is immediate.

Text width measured via GetTextExtentPoint32W against the currently
selected font so the anchoring decision uses the actual rendered
width, not a heuristic.

src/bubble.rs

@@ -1061,7 +1061,7 @@ fn render(hwnd: HWND) {
         pixels.fill(0);
 
         paint_background(pixels, &layout, &inputs);
-        paint_accent_stripe(pixels, &layout, inputs.model);
+        paint_accent_stripe(pixels, &layout, inputs.model, inputs.is_dark);
         paint_bars(pixels, &layout, &inputs);
         paint_text_layer(mem_dc, &layout, &inputs);
 
@@ -1141,8 +1141,8 @@ fn row_band(layout: &BarLayout, row_top: i32) -> (i32, i32) {
     (top, bot)
 }
 
-fn paint_accent_stripe(pixels: &mut [u32], layout: &BarLayout, model: TrayIconKind) {
-    let stripe = rgb_to_dib(accent_color_for(model));
+fn paint_accent_stripe(pixels: &mut [u32], layout: &BarLayout, model: TrayIconKind, is_dark: bool) {
+    let stripe = rgb_to_dib(accent_color_for(model, is_dark));
     for y in 0..layout.canvas_h {
         for x in 0..layout.accent_right {
             if !point_in_rounded_rect(x, y, layout.canvas_w, layout.canvas_h, layout.corner_radius) {
@@ -1153,10 +1153,19 @@ fn paint_accent_stripe(pixels: &mut [u32], layout: &BarLayout, model: TrayIconKi
     }
 }
 
-fn accent_color_for(model: TrayIconKind) -> Color {
+/// Per-provider identity color. Claude = orange. Codex = white-in-dark /
+/// charcoal-in-light — picking a pure white in light mode would vanish into
+/// the `#F3F3F3` background, so we mirror to a contrasting neutral.
+fn accent_color_for(model: TrayIconKind, is_dark: bool) -> Color {
     match model {
         ProviderId::Claude => Color::from_hex("#D97757"),
-        ProviderId::ChatGpt => Color::from_hex("#10A37F"),
+        ProviderId::ChatGpt => {
+            if is_dark {
+                Color::from_hex("#FFFFFF")
+            } else {
+                Color::from_hex("#2A2A2A")
+            }
+        }
     }
 }
 
@@ -1333,44 +1342,62 @@ fn draw_inline_percent(
         return;
     };
     let text = format!("{:.0}%", p);
-    let mut text_w = wide_str(&text);
-    let len_no_nul = text_w.len().saturating_sub(1);
 
-    // Pick the color: when the fill covers the right edge of the bar, the
-    // percent sits on the fill — contrast against the fill's color. Otherwise
-    // it sits on the track — contrast against the track.
+    // Measure the percent against the currently-selected font so we can
+    // anchor it to the fill's trailing edge rather than the bar's far right.
+    let mut wide: Vec<u16> = text.encode_utf16().collect();
+    let mut sz = windows::Win32::Foundation::SIZE::default();
+    unsafe {
+        let _ = GetTextExtentPoint32W(hdc, &mut wide, &mut sz);
+    }
+    let text_w = sz.cx;
+
     let bar_w = layout.bar_right - layout.bar_left;
     let fill_w = ((p.clamp(0.0, 100.0) / 100.0) * bar_w as f64).round() as i32;
+    let inset = (layout.bar_h / 4).max(2);
     let fill_color = ring_color_for_percent(p);
     let track_color = if is_dark {
         Color::from_hex("#3A3A3A")
     } else {
         Color::from_hex("#D6D6D6")
     };
-    // The percent sits at the right edge of the bar with a small inset; if
-    // fill_w covers most of the bar it lies on the fill, else on the track.
-    let on_fill = fill_w > bar_w * 2 / 3;
-    let underlying = if on_fill { fill_color } else { track_color };
+
+    // Two anchoring modes:
+    //  - Fill is wide enough to hold the percent → right-align the text
+    //    *inside* the fill at its trailing edge. The text sits on the fill.
+    //  - Fill is too narrow → left-align the text just to the right of the
+    //    fill, on the track. The text follows the fill's edge.
+    // Either way the percent is tethered to where the bar reaches.
+    let (text_left, underlying) = if fill_w >= text_w + inset * 2 {
+        let right = layout.bar_left + fill_w - inset;
+        ((right - text_w).max(layout.bar_left + inset), fill_color)
+    } else {
+        let left = layout.bar_left + fill_w + inset;
+        let clamped = left.min(layout.bar_right - text_w - inset).max(layout.bar_left + inset);
+        (clamped, track_color)
+    };
+
     let fg = if use_dark_text_over(underlying) {
         Color::from_hex("#101010")
     } else {
         Color::from_hex("#F5F5F5")
     };
 
-    let inset = (layout.bar_h / 3).max(3);
+    let mut text_buf = wide_str(&text);
+    let len_no_nul = text_buf.len().saturating_sub(1);
     let mut rect = RECT {
-        left: layout.bar_left,
+        left: text_left,
         top: row_top - 2,
-        right: layout.bar_right - inset,
+        right: (text_left + text_w).min(layout.bar_right),
         bottom: row_top + layout.bar_h + 2,
     };
     unsafe {
         SetTextColor(hdc, COLORREF(fg.into_colorref()));
         let _ = DrawTextW(
             hdc,
-            &mut text_w[..len_no_nul],
+            &mut text_buf[..len_no_nul],
             &mut rect,
-            DT_RIGHT | DT_VCENTER | DT_SINGLELINE | DT_NOCLIP,
+            DT_LEFT | DT_VCENTER | DT_SINGLELINE | DT_NOCLIP,
         );
     }
 }

src/panel.rs

@@ -277,10 +277,12 @@ fn paint(hwnd: HWND, hdc: HDC) {
         let _ = DeleteObject(bg_brush);
 
         // 4-px accent stripe matching the bubble — same provider color so the
-        // identity carries across both surfaces.
-        let stripe_color = match data.model {
-            ProviderId::Claude => Color::from_hex("#D97757"),
-            ProviderId::ChatGpt => Color::from_hex("#10A37F"),
+        // identity carries across both surfaces. Codex is theme-aware so a
+        // pure white stripe doesn't vanish into the light-mode background.
+        let stripe_color = match (data.model, data.is_dark) {
+            (ProviderId::Claude, _) => Color::from_hex("#D97757"),
+            (ProviderId::ChatGpt, true) => Color::from_hex("#FFFFFF"),
+            (ProviderId::ChatGpt, false) => Color::from_hex("#2A2A2A"),
         };
         let stripe_w = scaled(4);
         let stripe_rect = RECT {