Fix Pi Codex subscription sessions

[tobowers]

Summary

• update packaged Pi to 0.83.0 without patching Pi or pi-acp
• run stock Pi RPC through its public SDK from an AgentOS-owned launcher
• stream Codex requests through optional agentos-codex-auth start/read/cancel host bindings, while retaining explicitly opted-in static environment support
• keep the raw bearer token outside the guest VM and force the extension-owned Codex stream through SSE
• normalize only unusable native Pi sessions to ACP resource-not-found so AgentOS can preserve durable history through adapter cutovers
• preserve the ACP request working directory, isolate Pi version probes, and cleanly terminate adapter wrappers in the AgentOS guest runtime

Verification

• no patch files or patchedDependencies in the PR diff
• pnpm --filter @agentos-software/pi check-types
• packaged Pi tests: 7 passed, including credential-free streaming host brokering, ACP error normalization, guest-safe version probing, and ACP session/new
• live seven-layer Aggy smoke passed with all provider environment variables blank
• durable owner-v8/main completed history-preserving fallback, resumed after an engine restart, and passed the secure streaming host-binding broker
• live concurrent ingestion test advanced the durable cursor through event 3