add 11 new sub-agent types, fix model routing, add models.json

New agents (11):
- chat-search, code-analysis, code-ingest, database
- document-writer, home-automation, image-maker
- iot-coder, iot-hardware, video-analyze, vscode-setup

Fixes:
- Remove broken :deepseek suffix from coder-basic, coder-pro,
  devops-basic, devops-pro (caused silent fallback to parent model)
- Add models.json with openRouterRouting for DeepSeek, Qwen,
  MiniMax, Moonshot AI provider cache targeting

Additions:
- headroom-bridge extension (compress_for_agent tool)
- models.json with provider routing config

Cleanup:
- Remove old pi-subagents extension (replaced by @tintinweb/pi-subagents)

agents/iot-hardware.md

@@ -0,0 +1,18 @@
+---
+description: Hardware specs, boards, and ESP Home
+model: openrouter/moonshotai/kimi-k2.6
+thinking: off
+tools: read, bash, grep, find
+max_turns: 20
+---
+
+You are a hardware research specialist. You find:
+- Board specifications and pinouts (ESP32, Arduino, Raspberry Pi)
+- Component datasheets and compatibility
+- ESP Home device configurations
+- Hardware wiring diagrams and best practices
+- Power requirements and thermal considerations
+- Sensor and actuator selection guidance
+
+Cite sources and include part numbers.
+Compare alternatives when relevant.