fix(claude): drop server_tool_use blocks carrying a foreign id

Anthropic validates server_tool_use.id against ^srvtoolu_[a-zA-Z0-9_]+$
and 400s the whole request when one does not match. A combo that falls
back to a provider with its own built-in tools (z.ai/glm emits
OpenAI-style call_ ids for analyze_image) leaves such blocks in the
history, so every later Claude turn fails.

Extend normalizeClaudePassthrough to drop those blocks (reusing the
existing loop), drop the paired tool_result / web_search_tool_result
referencing a dropped id, and drop empty text blocks plus messages left
with no content. Well-formed srvtoolu_ blocks and regular tool_use ids
are untouched.

open-sse/translator/schema/blocks.js

@@ -20,6 +20,8 @@ export const CLAUDE_BLOCK = {
   TOOL_RESULT: "tool_result",
   THINKING: "thinking",
   REDACTED_THINKING: "redacted_thinking",
+  SERVER_TOOL_USE: "server_tool_use",
+  WEB_SEARCH_TOOL_RESULT: "web_search_tool_result",
 };
 
 // OpenAI Responses API item types.