优化: 溢出修复与视觉token收敛+三处小清理

- diff长行折行可读/任务描述与产出宽表格横滚/确认弹窗长路径折行
- 滚动条色抽token浅色主题可见/阶段徽章与优先级色对齐语义token
- git状态色与错误色替换散落硬编码
- alert残留换toast走i18n/分离窗口缺参数补错误态/dev路由生产守卫

src/views/ProjectDetail.vue

@@ -1427,13 +1427,14 @@ onUnmounted(() => {
   border-radius: var(--df-radius-lg);
   font-weight: 500;
 }
-.stage-planning { background: rgba(100,181,246,0.15); color: #64b5f6; }
+/* 阶段色全走语义 token(对齐全站约定:releasing/completed=success,见 ActiveProjectsPanel dot-release) */
+.stage-planning { background: var(--df-info-bg); color: var(--df-info); }
 .stage-in_progress { background: var(--df-accent-soft); color: var(--df-accent); }
-.stage-testing { background: rgba(255,193,7,0.15); color: #ffc107; }
-.stage-releasing { background: rgba(156,39,176,0.15); color: #ce93d8; }
-.stage-completed { background: rgba(100,200,100,0.15); color: #64c864; }
-.stage-paused { background: rgba(158,158,158,0.15); color: #9e9e9e; }
-.stage-cancelled { background: rgba(244,67,54,0.15); color: #f44336; }
+.stage-testing { background: var(--df-warning-bg); color: var(--df-warning); }
+.stage-releasing { background: var(--df-success-bg); color: var(--df-success); }
+.stage-completed { background: var(--df-success-bg); color: var(--df-success); }
+.stage-paused { background: rgba(158,158,158,0.15); color: var(--df-text-dim); }
+.stage-cancelled { background: var(--df-danger-bg); color: var(--df-danger); }
 
 /* .header-actions 已提取到 styles/global.css 全局 */