zen: add opus 4.5

Author: Frank

packages/web/src/content/docs/zen.mdx

@@ -73,6 +73,7 @@ You can also access our models through the following API endpoints.
 | Claude Sonnet 4   | claude-sonnet-4   | `https://opencode.ai/zen/v1/messages`            | `@ai-sdk/anthropic`         |
 | Claude Haiku 4.5  | claude-haiku-4-5  | `https://opencode.ai/zen/v1/messages`            | `@ai-sdk/anthropic`         |
 | Claude Haiku 3.5  | claude-3-5-haiku  | `https://opencode.ai/zen/v1/messages`            | `@ai-sdk/anthropic`         |
+| Claude Opus 4.5   | claude-opus-4-5   | `https://opencode.ai/zen/v1/messages`            | `@ai-sdk/anthropic`         |
 | Claude Opus 4.1   | claude-opus-4-1   | `https://opencode.ai/zen/v1/messages`            | `@ai-sdk/anthropic`         |
 | Gemini 3 Pro      | gemini-3-pro      | `https://opencode.ai/zen/v1/models/gemini-3-pro` | `@ai-sdk/google`            |
 | GLM 4.6           | glm-4.6           | `https://opencode.ai/zen/v1/chat/completions`    | `@ai-sdk/openai-compatible` |
@@ -130,6 +131,7 @@ We support a pay-as-you-go model. Below are the prices **per 1M tokens**.
 | Claude Sonnet 4 (> 200K tokens)   | $6.00  | $22.50 | $0.60       | $7.50        |
 | Claude Haiku 4.5                  | $1.00  | $5.00  | $0.10       | $1.25        |
 | Claude Haiku 3.5                  | $0.80  | $4.00  | $0.08       | $1.00        |
+| Claude Opus 4.5                   | $5.00  | $25.00 | $0.50       | $6.25        |
 | Claude Opus 4.1                   | $15.00 | $75.00 | $1.50       | $18.75       |
 | Gemini 3 Pro (≤ 200K tokens)      | $2.00  | $12.00 | $0.20       | -            |
 | Gemini 3 Pro (> 200K tokens)      | $4.00  | $18.00 | $0.40       | -            |