feat: Anthropic web server tools, provider metadata, messaging hardening

- Add local web_search/web_fetch SSE handling and optional tool schemas
- Extend HeuristicToolParser for JSON-style WebFetch/WebSearch text
- Consolidate provider defaults, ids, and exception typing; stream contracts
- Messaging: typed options, voice config injection, platform contract cleanup
- Tests for web server tools, converters, parsers, contracts; ignore debug-*.log

tests/api/test_web_server_tools.py

@@ -0,0 +1,96 @@
+import json
+
+import pytest
+
+from api.models.anthropic import Message, MessagesRequest, Tool
+from api.web_server_tools import (
+    is_web_server_tool_request,
+    stream_web_server_tool_response,
+)
+
+
+def _event_data(event: str) -> dict:
+    data_line = next(line for line in event.splitlines() if line.startswith("data: "))
+    return json.loads(data_line.removeprefix("data: "))
+
+
+def test_detects_web_search_server_tool_request():
+    request = MessagesRequest(
+        model="claude-haiku-4-5-20251001",
+        max_tokens=100,
+        messages=[Message(role="user", content="search")],
+        tools=[Tool(name="web_search", type="web_search_20250305")],
+    )
+
+    assert is_web_server_tool_request(request)
+
+
+@pytest.mark.asyncio
+async def test_streams_web_search_server_tool_result(monkeypatch):
+    async def fake_search(query: str) -> list[dict[str, str]]:
+        assert query == "DeepSeek V4 model release 2026"
+        return [{"title": "DeepSeek V4 Released", "url": "https://example.com/v4"}]
+
+    monkeypatch.setattr("api.web_server_tools._run_web_search", fake_search)
+    request = MessagesRequest(
+        model="claude-haiku-4-5-20251001",
+        max_tokens=100,
+        messages=[
+            Message(
+                role="user",
+                content=(
+                    "Perform a web search for the query: DeepSeek V4 model release 2026"
+                ),
+            )
+        ],
+        tools=[Tool(name="web_search", type="web_search_20250305")],
+        tool_choice={"type": "tool", "name": "web_search"},
+    )
+
+    events = [
+        event
+        async for event in stream_web_server_tool_response(request, input_tokens=42)
+    ]
+    payloads = [_event_data(event) for event in events]
+
+    assert payloads[1]["content_block"]["type"] == "server_tool_use"
+    assert payloads[1]["content_block"]["name"] == "web_search"
+    assert payloads[3]["content_block"]["type"] == "web_search_tool_result"
+    assert payloads[3]["content_block"]["content"][0]["url"] == "https://example.com/v4"
+    assert payloads[-2]["usage"]["server_tool_use"] == {"web_search_requests": 1}
+
+
+@pytest.mark.asyncio
+async def test_streams_web_fetch_server_tool_result(monkeypatch):
+    async def fake_fetch(url: str) -> dict[str, str]:
+        assert url == "https://example.com/article"
+        return {
+            "url": url,
+            "title": "Example Article",
+            "media_type": "text/plain",
+            "data": "Article body",
+        }
+
+    monkeypatch.setattr("api.web_server_tools._run_web_fetch", fake_fetch)
+    request = MessagesRequest(
+        model="claude-haiku-4-5-20251001",
+        max_tokens=100,
+        messages=[
+            Message(role="user", content="Fetch https://example.com/article please")
+        ],
+        tools=[Tool(name="web_fetch", type="web_fetch_20250910")],
+        tool_choice={"type": "tool", "name": "web_fetch"},
+    )
+
+    events = [
+        event
+        async for event in stream_web_server_tool_response(request, input_tokens=42)
+    ]
+    payloads = [_event_data(event) for event in events]
+
+    assert payloads[1]["content_block"]["type"] == "server_tool_use"
+    assert payloads[3]["content_block"]["type"] == "web_fetch_tool_result"
+    assert payloads[3]["content_block"]["content"]["content"]["title"] == (
+        "Example Article"
+    )
+    assert payloads[-2]["usage"]["server_tool_use"] == {"web_fetch_requests": 1}