feat: M6.40批 — 阅读器UI改版(书架list·grid+空态骨架+界面设置+App设置页+header·footer+背景黑默认) + 系统级音量翻页映射 + P1 MD3(select面板28/对话框按钮胶囊) + MeowPanel写端点护栏 + SDK公开仓·文档同步

- reader: app.c/shelf.c/reader.c 全套UI; 新增 reader_conf(reader.conf)/settings(App设置页)/reader_ipc(音量翻页IPC响应); app.json加volume_page
- launcher: keys.c meow_volpage_*门 + util.c app_id→fd映射(HELLO记fd/断开清) + app_launcher.c 前台三处接线(进入sink/按键路径volpage_key/离开clear) → 前台声明volume_page的App音量键→MSG_KEY_PAGEUP/PAGEDOWN翻页(非阅读器前台音量照旧)
- sdk: meow_select.c 底部面板28 + meow_ui_dialog.c 对话框按钮胶囊(h/2) + test_meow_ui_select.c修采样
- meowpanel: /api/net/policy·/api/power/policy 加防自锁+policy默认关两条护栏(panel.policy_enabled默认0)
- 文档: MEOW_APP_SDK.md §12.6 + meowpanel README端点表

0warning;宿主测试全过;二进制留批量批次未入库

patch_v2/sdk/meow_ui_dialog.c

@@ -134,12 +134,13 @@ static void dlg_card(meow_dialog *d, const meow_theme *th, const dlg_geom *g)
                 y += meow_ui_text_height(th->font_body) + 8;
             }
         }
-        /* 取消（左，text 型）/ 确定（右，filled） */
+        /* 取消（左，outlined）/ 确定（右，filled）——MD3 按钮统一为胶囊（full，全高一半），
+         * 与 SDK widget_btn_radius(meow_ui_widget.c:146) 同款；旧硬编码 radius 10 非 token。 */
         int bx = g->dx + pad, cx = bx + g->btn_w + 12, by = g->btn_y;
-        meow_ui_draw_rect_round(bx, by, g->btn_w, g->btn_h, 10, th->primary);
+        meow_ui_draw_rect_round(bx, by, g->btn_w, g->btn_h, MEOW_SHAPE_FULL(g->btn_h), th->primary);
         meow_ui_text_center(bx + g->btn_w / 2, by + (g->btn_h - meow_ui_text_height(th->font_body)) / 2,
                             meow_str("common.cancel"), th->font_body, th->primary);
-        meow_gfx_fill_round(cx, by, g->btn_w, g->btn_h, 10, th->primary);
+        meow_gfx_fill_round(cx, by, g->btn_w, g->btn_h, MEOW_SHAPE_FULL(g->btn_h), th->primary);
         meow_ui_text_center(cx + g->btn_w / 2, by + (g->btn_h - meow_ui_text_height(th->font_body)) / 2,
                             meow_str("common.ok"), th->font_body, th->onPrimary);
     }