Added a stack view in bottom panel

src/simulator/gui_tab_stack.odin

@@ -0,0 +1,63 @@
+package simulator
+import "core:fmt"
+import rl "vendor:raylib"
+
+gui_tab_stack :: proc(rect: rl.Rectangle, sim: ^Simulator) {
+	// Panel below header
+	panel_rect := rl.Rectangle{
+		rect.x,
+		rect.y + PANEL_HEADER,
+		rect.width,
+		rect.height - PANEL_HEADER,
+	}
+	rl.GuiPanel(panel_rect, nil)
+
+	// Header background
+	rl.DrawRectangle(i32(rect.x), i32(rect.y), i32(rect.width), i32(PANEL_HEADER), rl.BLACK)
+	rl.DrawTextEx(sim.font, "Stack", {rect.x + 4, rect.y + 4}, 18, 1, rl.WHITE)
+
+	// SP indicator in header
+	sp_label := fmt.ctprintf("SP: %d", sim.machine.sp)
+	sp_size  := rl.MeasureTextEx(sim.font, sp_label, 18, 1)
+	rl.DrawTextEx(sim.font, sp_label, {rect.x + rect.width - sp_size.x - 8, rect.y + 4}, 18, 1, rl.WHITE)
+
+	// Use full panel height so empty slots fill the space
+	total_height := max(f32(16) * LINE_HEIGHT, panel_rect.height)
+	content_rect := rl.Rectangle{
+		x      = panel_rect.x,
+		y      = panel_rect.y - PANEL_HEADER,
+		width  = panel_rect.width - 15,
+		height = total_height,
+	}
+	view: rl.Rectangle
+	rl.GuiScrollPanel(panel_rect, nil, content_rect, &sim.stack_scroll, &view)
+	rl.BeginScissorMode(i32(view.x), i32(view.y), i32(view.width), i32(view.height))
+	defer rl.EndScissorMode()
+
+	index_x := panel_rect.x + PADDING_X
+	colon_x := index_x + 30
+
+	for i in 0..<16 {
+		y_pos     := panel_rect.y + (f32(i) * LINE_HEIGHT) + sim.stack_scroll.y
+		is_active := i < int(sim.machine.sp)
+		is_top    := i == int(sim.machine.sp) - 1
+		// Only draw a background for active slots
+		if is_active {
+			rl.DrawRectangleV(
+				{panel_rect.x + sim.stack_scroll.x, y_pos},
+				{panel_rect.width, LINE_HEIGHT},
+				rl.BLACK,
+			)
+		}
+		sp_marker := ""
+		if is_top do sp_marker = " <- SP"
+
+		color := rl.WHITE if is_top else (rl.BLACK if is_active else rl.WHITE)
+
+		txt_index := fmt.ctprintf("%02d", i)
+		txt_value := fmt.ctprintf(": 0x%04X%s", sim.machine.stack[i], sp_marker)
+
+		rl.DrawTextEx(sim.font, txt_index, {index_x + sim.stack_scroll.x, y_pos}, 18, 1, color)
+		rl.DrawTextEx(sim.font, txt_value, {colon_x + sim.stack_scroll.x, y_pos}, 18, 1, color)
+	}
+}