refactor(opencode): build runtimes from layer nodes

[jlongster]

Summary

• build AppRuntime and BootstrapRuntime through AppNodeBuilder graphs
• update runtime helper entrypoints to use node-built layers
• add a node for the websocket tracker so listener setup no longer consumes its exported layer

Testing

• bun typecheck
• bun turbo typecheck (pre-push)

Stack

1. refactor(opencode): build runtimes from layer nodes #34515 refactor(opencode): build runtimes from layer nodes
2. refactor(opencode): use layer nodes in remaining harnesses #34516 refactor(opencode): use layer nodes in remaining harnesses
3. refactor(opencode): remove app service layer exports #34517 refactor(opencode): remove app service layer exports
4. refactor(opencode): remove core service layer exports #34518 refactor(opencode): remove core service layer exports
5. refactor(opencode): keep plugin pty environment route local #34519 refactor(opencode): keep plugin pty environment route local

Base: dev
Next: #34516