Rename RealTimeSearchTool → WeatherTool, fetch Balashikha weather via SearXNG

WeatherTool queries SearXNG with a fixed 'weather Balashikha Moscow now'
query instead of passing the user message as-is. SearXNG has external
internet access and returns snippets with actual current conditions.
Direct wttr.in fetch not possible — deepagents container has no external
internet routing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

agent.py

@@ -24,7 +24,7 @@ from langchain_core.tools import Tool
 from vram_manager import VRAMManager
 from router import Router
 from agent_factory import build_medium_agent, build_complex_agent
-from fast_tools import FastToolRunner, RealTimeSearchTool
+from fast_tools import FastToolRunner, WeatherTool
 import channels
 
 # Bifrost gateway — all LLM inference goes through here
@@ -121,7 +121,7 @@ _memory_search_tool = None
 
 # Fast tools run before the LLM — classifier + context enricher
 _fast_tool_runner = FastToolRunner([
-    RealTimeSearchTool(searxng_url=SEARXNG_URL),
+    WeatherTool(searxng_url=SEARXNG_URL),
 ])
 
 # GPU mutex: one LLM inference at a time