docs: improve README product previews

.github/readme-assets/asset-manifest.json

@@ -0,0 +1,38 @@
+{
+  "ui_assets_complete": true,
+  "semantic_media_policy": "Use real ReplyPier interface captures; do not substitute generated product mockups.",
+  "assets": [
+    {
+      "file": "replypier-agent-customization.png",
+      "role": "AI agent appearance editor and live widget preview",
+      "source": "Saved local ReplyPier interface capture, cropped to the main workspace",
+      "alt": "ReplyPier 客服配置工作台，左侧调整聊天外观，右侧即时预览访客窗口",
+      "usage": "README product overview"
+    },
+    {
+      "file": "replypier-visitor-chat.png",
+      "role": "Visitor-facing chat widget",
+      "source": "User-provided real widget capture; the avatar marks were updated to the selected paper-boat brand asset",
+      "alt": "ReplyPier 网站客服聊天窗口，纸舟标志显示在客服头像与页脚图标处",
+      "usage": "README visitor-side preview"
+    }
+  ],
+  "omitted": [
+    {
+      "item": "Generated service-flow illustration and 340 x 280 widget crop",
+      "reason": "Replaced with two larger, distinct interface views"
+    }
+  ],
+  "qa": [
+    {
+      "file": "replypier-agent-customization.png",
+      "status": "passed",
+      "checks": ["chrome controls removed", "live preview visible", "alt text present"]
+    },
+    {
+      "file": "replypier-visitor-chat.png",
+      "status": "passed",
+      "checks": ["full widget visible", "paper-boat marks applied", "message text preserved", "alt text present"]
+    }
+  ]
+}