feat: remove charmap in-window header, float the copy toast

The top header bar duplicated the window-manager title bar. Drop it: tabs
now sit at the top of the content area (window shrinks by the header's
height). The "Copied" confirmation moves from the header to a floating
accent toast anchored to the lower-right of the grid, drawn last.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

programs/src/charmap/main.cpp

@@ -197,8 +197,7 @@ static constexpr int SET_COUNT = (int)(sizeof(SETS) / sizeof(SETS[0]));
 // ==== Layout constants ====
 
 static constexpr int INIT_W    = 680;
-static constexpr int INIT_H    = 500;
+static constexpr int INIT_H    = 448;
-static constexpr int HEADER_H  = 52;
 static constexpr int TAB_H     = 40;
 static constexpr int FOOTER_H  = 84;
 static constexpr int GRID_PAD  = 12;
@@ -206,7 +205,6 @@ static constexpr int CELL_GAP  = 6;
 static constexpr int CELL_TARGET = 54;   // desired tile edge in px
 static constexpr int SCROLLBAR_W = 8;
 
-static constexpr int TITLE_SIZE = 20;
 static constexpr int TAB_SIZE   = 16;
 static constexpr int CELL_SIZE  = 26;    // glyph font size inside a tile
 static constexpr int PREVIEW_SIZE = 40;
@@ -233,7 +231,6 @@ static mtk::Theme g_theme;
 // ==== Derived layout ====
 
 struct Layout {
-    Rect header;
     Rect tabs;
     Rect grid;      // interior area available for the tile grid
     Rect footer;
@@ -249,9 +246,8 @@ static const CharSet& cur_set() { return SETS[g_set]; }
 
 static Layout compute_layout(int w, int h) {
     Layout L {};
-    L.header = { 0, 0, w, HEADER_H };
+    L.tabs   = { 0, 0, w, TAB_H };
-    L.tabs   = { 0, HEADER_H, w, TAB_H };
+    int grid_top = TAB_H;
-    int grid_top = HEADER_H + TAB_H;
     L.footer = { 0, h - FOOTER_H, w, FOOTER_H };
     L.grid   = { GRID_PAD, grid_top + GRID_PAD,
                  w - GRID_PAD * 2, (h - FOOTER_H) - grid_top - GRID_PAD * 2 };
@@ -425,27 +421,10 @@ static void render(Canvas& c) {
     }
     c.fill_rect(L.tabs.x, L.tabs.y + L.tabs.h - 1, L.tabs.w, 1, g_theme.border);
 
-    // ---- Header (opaque) ----
+    // Bold font for the footer name and Copy button.
-    c.fill_rect(L.header.x, L.header.y, L.header.w, L.header.h, g_theme.window_bg);
     TrueTypeFont* title_font =
         (fonts::system_bold && fonts::system_bold->valid) ? fonts::system_bold
                                                           : fonts::system_font;
-    int title_h = text_height(title_font, TITLE_SIZE);
-    draw_text(c, title_font, GRID_PAD, (HEADER_H - title_h) / 2,
-              "Character Map", g_theme.text, TITLE_SIZE);
-
-    // Toast pill (right side of header).
-    if (g_toast[0] && montauk::get_milliseconds() < g_toast_until) {
-        int tw = text_width(fonts::system_font, g_toast, TOAST_SIZE);
-        int pill_w = tw + 24, pill_h = 26;
-        int px = c.w - GRID_PAD - pill_w;
-        int py = (HEADER_H - pill_h) / 2;
-        c.fill_rounded_rect(px, py, pill_w, pill_h, pill_h / 2, g_theme.accent_soft);
-        draw_text(c, fonts::system_font, px + 12,
-                  py + (pill_h - text_height(fonts::system_font, TOAST_SIZE)) / 2,
-                  g_toast, g_theme.accent_hover, TOAST_SIZE);
-    }
-    c.fill_rect(L.header.x, L.header.y + L.header.h - 1, L.header.w, 1, g_theme.border);
 
     // ---- Footer (opaque) ----
     c.fill_rect(L.footer.x, L.footer.y, L.footer.w, L.footer.h, g_theme.surface_alt);
@@ -480,6 +459,18 @@ static void render(Canvas& c) {
     draw_button(c, title_font, L.copy_btn.x, L.copy_btn.y, L.copy_btn.w,
                 L.copy_btn.h, "Copy", btn_bg, g_theme.accent_fg,
                 g_theme.radius_md, TAB_SIZE);
+
+    // ---- Toast (drawn last; floats over the lower-right of the grid) ----
+    if (g_toast[0] && montauk::get_milliseconds() < g_toast_until) {
+        int tw = text_width(fonts::system_font, g_toast, TOAST_SIZE);
+        int pill_w = tw + 24, pill_h = 28;
+        int px = c.w - GRID_PAD - pill_w;
+        int py = L.footer.y - GRID_PAD - pill_h;
+        c.fill_rounded_rect(px, py, pill_w, pill_h, pill_h / 2, g_theme.accent);
+        draw_text(c, fonts::system_font, px + 12,
+                  py + (pill_h - text_height(fonts::system_font, TOAST_SIZE)) / 2,
+                  g_toast, g_theme.accent_fg, TOAST_SIZE);
+    }
 }
 
 // ==== Event handling ====