feat(zai): add Web Search in Chat integration for Z.AI provider

[oldschoola]

Summary

Adds Z.AI's built-in Web Search in Chat feature to the Anthropic-compatible chat completions pipeline. When enabled, a web_search tool is injected into requests to Z.AI endpoints, allowing the model to search the web natively and return cited answers.

What it does

• Injects web_search_20250305 built-in tool into requests when the model targets a Z.AI Anthropic-compatible endpoint and zai.webSearchInChat is enabled
• Handles response blocks: server_tool_use (search tool calls), web_search_tool_result (Anthropic native), and tool_result (Z.AI's format for search results)
• Parses search results from Z.AI's JSON content and formats them as readable links with titles
• Settings: zai.webSearchInChat (enable/disable), zai.webSearchCount (1-50 results), zai.webSearchRecency (time range filter)

Files changed

File	Change
packages/ai/src/providers/anthropic-wire.ts	Added ServerToolUseBlockParam, WebSearchResultItem, WebSearchToolResultBlockParam types
packages/ai/src/providers/anthropic.ts	Added ZaiWebSearchConfig type, tool injection in buildParams, stream handler for new block types
packages/ai/src/stream.ts	Pass zaiWebSearch through mapOptionsForApi
packages/ai/src/types.ts	Added zaiWebSearch to SimpleStreamOptions
packages/coding-agent/src/config/settings-schema.ts	Added zai.webSearchInChat, zai.webSearchCount, zai.webSearchRecency settings
packages/coding-agent/src/sdk.ts	Wired settings to streamFn options

Testing

Verified with Z.AI API key:

• ✅ Direct Web Search REST API works
• ✅ Anthropic-compatible endpoint accepts web_search_20250305 tool
• ✅ Streaming returns text, server_tool_use, tool_result blocks
• ✅ tool_result content is JSON with search results (title, link, content, refer)
• ✅ TypeScript compiles with zero new errors
• ✅ Biome formatting passes

Usage

Set in settings or via env:

zai.webSearchInChat: true
zai.webSearchCount: 5        # optional, default 5
zai.webSearchRecency: noLimit # optional, default noLimit

Requires ZAI_API_KEY to be set.