docs(pricing): add Seedream 5.0 Pro pricing

Author: lin-bot23

tutorials/partner-nodes/pricing.mdx

@@ -89,15 +89,18 @@ Per million tokens. Rates below are for prompt length **[0, 128]K**; longer prom
 
 Optional images and videos add input tokens at the input rate.
 
-### Image: ByteDance Seedream 4.5 & 5.0
+### Image: ByteDance Seedream
 
 Per successfully generated image.
 
-| model                                     | Credits / image |
-| :---------------------------------------- | :-------------: |
-| seedream 5.0 lite (`seedream-5-0-260128`) |      7.39       |
-| seedream-4-5-251128                       |      8.44       |
-| seedream-4-0-250828                       |      6.33       |
+| model                                               | Credits / image      |
+| :-------------------------------------------------- | :------------------- |
+| seedream 5.0 pro (`seedream-5-0-pro-260628`)        | 9.50 (1K) / 18.99 (2K) |
+| seedream 5.0 lite (`seedream-5-0-260128`)           | 7.39                 |
+| seedream-4-5-251128                                 | 8.44                 |
+| seedream-4-0-250828                                 | 6.33                 |
+
+Seedream 5.0 Pro uses resolution-based billing: **1K** (≤2.36 MP, $0.045) and **2K** (>2.36 MP, $0.09). The first image in each request is free. Each additional image beyond the first (including both output and input/reference images) adds **$0.003** (**0.63 credits**).
 
 ### Image: ByteDance Image (deprecated)