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

api/app.py

@@ -2,8 +2,11 @@
 
 import os
 from contextlib import asynccontextmanager
+from typing import Any
 
 from fastapi import FastAPI, Request
+from fastapi.exception_handlers import request_validation_exception_handler
+from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
 from loguru import logger
 
@@ -11,7 +14,6 @@ from config.logging_config import configure_logging
 from config.settings import get_settings
 from providers.exceptions import ProviderError
 
-from .dependencies import cleanup_provider
 from .routes import router
 from .runtime import AppRuntime
 
@@ -26,9 +28,7 @@ configure_logging(_settings.log_file)
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     """Application lifespan manager."""
-    runtime = AppRuntime.for_app(
-        app, settings=get_settings(), provider_cleanup=cleanup_provider
-    )
+    runtime = AppRuntime.for_app(app, settings=get_settings())
     await runtime.startup()
 
     yield
@@ -48,6 +48,60 @@ def create_app() -> FastAPI:
     app.include_router(router)
 
     # Exception handlers
+    @app.exception_handler(RequestValidationError)
+    async def validation_error_handler(request: Request, exc: RequestValidationError):
+        """Log request shape for 422 debugging without content values."""
+        body: Any
+        try:
+            body = await request.json()
+        except Exception as e:
+            body = {"_json_error": type(e).__name__}
+
+        messages = body.get("messages") if isinstance(body, dict) else None
+        message_summary: list[dict[str, Any]] = []
+        if isinstance(messages, list):
+            for msg in messages:
+                if not isinstance(msg, dict):
+                    message_summary.append({"message_kind": type(msg).__name__})
+                    continue
+                content = msg.get("content")
+                item: dict[str, Any] = {
+                    "role": msg.get("role"),
+                    "content_kind": type(content).__name__,
+                }
+                if isinstance(content, list):
+                    item["block_types"] = [
+                        block.get("type", "dict")
+                        if isinstance(block, dict)
+                        else type(block).__name__
+                        for block in content[:12]
+                    ]
+                    item["block_keys"] = [
+                        sorted(str(key) for key in block)[:12]
+                        for block in content[:5]
+                        if isinstance(block, dict)
+                    ]
+                elif isinstance(content, str):
+                    item["content_length"] = len(content)
+                message_summary.append(item)
+
+        logger.debug(
+            "Request validation failed: path={} query={} error_locs={} error_types={} message_summary={} tool_names={}",
+            request.url.path,
+            str(request.url.query),
+            [list(error.get("loc", ())) for error in exc.errors()],
+            [str(error.get("type", "")) for error in exc.errors()],
+            message_summary,
+            [
+                str(tool.get("name", ""))
+                for tool in body.get("tools", [])
+                if isinstance(body, dict)
+                and isinstance(body.get("tools"), list)
+                and isinstance(tool, dict)
+            ],
+        )
+        return await request_validation_exception_handler(request, exc)
+
     @app.exception_handler(ProviderError)
     async def provider_error_handler(request: Request, exc: ProviderError):
         """Handle provider-specific errors and return Anthropic format."""