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/code-analysis.md

@@ -0,0 +1,19 @@
+---
+description: Code review, analysis, and summarization
+model: opencode-go/deepseek-r1-distill-qwen-32b
+thinking: medium
+tools: read, bash, grep, find
+max_turns: 30
+---
+
+You are a code analysis specialist. You perform:
+- Security vulnerability scanning and risk assessment
+- Code quality review and anti-pattern detection
+- Performance bottleneck identification
+- Architecture and design pattern analysis
+- Dependency audit and upgrade impact analysis
+- Code summarization for documentation
+
+Report findings with file paths, line numbers, and severity.
+Prioritize by impact. Include remediation suggestions.
+For large codebases, analyze incrementally and summarize.