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/components/project/FilePreview.vue

@@ -641,7 +641,7 @@ onUnmounted(() => {
 }
 
 .preview-size { color: var(--df-text-dim); flex-shrink: 0; }
-.preview-truncated { color: #f0a020; flex-shrink: 0; }
+.preview-truncated { color: var(--df-git-modified); flex-shrink: 0; }
 
 .git-badge {
   flex-shrink: 0;
@@ -655,7 +655,7 @@ onUnmounted(() => {
 
 .git-modified { background: color-mix(in srgb, var(--df-git-modified) 18%, transparent); color: var(--df-git-modified); }
 .git-added { background: color-mix(in srgb, var(--df-git-added) 18%, transparent); color: var(--df-git-added); }
-.git-untracked { background: rgba(150, 150, 150, 0.18); color: #999; }
+.git-untracked { background: rgba(150, 150, 150, 0.18); color: var(--df-git-untracked); }
 .git-deleted { background: color-mix(in srgb, var(--df-git-deleted) 18%, transparent); color: var(--df-git-deleted); }
 .git-other { background: color-mix(in srgb, var(--df-git-untracked) 18%, transparent); color: var(--df-git-untracked); }
 
@@ -737,7 +737,7 @@ onUnmounted(() => {
   font-size: 13px;
 }
 
-.preview-error { color: #e05050; }
+.preview-error { color: var(--df-danger); }
 .binary-icon { font-size: 32px; opacity: 0.5; }
 
 .preview-image {
@@ -1062,7 +1062,9 @@ onUnmounted(() => {
 
 .diff-line-text {
   flex: 1;
-  white-space: pre;
+  /* pre-wrap + break-all:diff 长行折行显示,替代旧 pre+hidden 的静默裁剪(内容不可达) */
+  white-space: pre-wrap;
+  word-break: break-all;
   overflow: hidden;
 }