feat(canvas): 新增视频节点字幕体系与多轨时间线编辑（关联 #187） (#191)

* fix(ci): 后端测试 - 修复 responses 流式测试数据与 Grok 生图测试 SSRF 放行

* feat(canvas): 新增视频节点字幕体系与多轨时间线编辑（关联 #187）

---------

Co-authored-by: zhaoyue <zhaoyue@rongshantech.com>

web/src/lib/canvas-theme.ts

@@ -43,6 +43,21 @@ export const canvasThemes = {
             glowStrong: "rgba(79,110,232,.52)",
             shadow: "rgba(15,23,42,.18)",
         },
+        // 时间线/字幕组件语义色：轨道底、按类型区分的片段、标尺与播放头、字幕列表条目态。
+        timeline: {
+            trackFill: "#f6f8fb",
+            trackBorder: "rgba(17,24,39,.08)",
+            clipVideo: "rgba(79,110,232,.16)",
+            clipAudio: "rgba(16,185,129,.14)",
+            clipSubtitle: "rgba(245,158,11,.16)",
+            clipSelectedBorder: "#4f6ee8",
+            handle: "rgba(255,255,255,.72)",
+            rulerTick: "rgba(17,24,39,.28)",
+            rulerLabel: "#6b7280",
+            playhead: "#4f6ee8",
+            entryActive: "rgba(79,110,232,.10)",
+            entryHover: "rgba(17,24,39,.05)",
+        },
         accent: {
             primary: "#4f6ee8",
             primarySoft: "rgba(79,110,232,.14)",
@@ -90,6 +105,20 @@ export const canvasThemes = {
             glowStrong: "rgba(143,155,214,.48)",
             shadow: "rgba(0,0,0,.6)",
         },
+        timeline: {
+            trackFill: "#101114",
+            trackBorder: "rgba(255,255,255,.08)",
+            clipVideo: "rgba(96,126,234,.22)",
+            clipAudio: "rgba(16,185,129,.20)",
+            clipSubtitle: "rgba(245,158,11,.20)",
+            clipSelectedBorder: "#8f9bd6",
+            handle: "rgba(255,255,255,.5)",
+            rulerTick: "rgba(255,255,255,.26)",
+            rulerLabel: "#a3a3a3",
+            playhead: "#8f9bd6",
+            entryActive: "rgba(96,126,234,.16)",
+            entryHover: "rgba(255,255,255,.06)",
+        },
         accent: {
             primary: "#8f9bd6",
             primarySoft: "rgba(107,120,190,.2)",