Align CloudShell FOG session/audit contracts with TurtleTerm receipts

[mdheller]

Summary

TurtleTerm now exists as the SourceOS policy-aware, agent-addressable terminal workbench. CloudShell FOG now has a mature session API, PTY attach model, placement metadata, audit events, OpenAPI schema, and k8s execution path.

The remaining integration gap is that CloudShell FOG does not yet define a first-class integration profile for TurtleTerm's SourceOS terminal event and receipt contracts.

Why this matters

TurtleTerm emits SourceOS terminal sessions, command lifecycle events, and durable command receipts. CloudShell FOG emits session/audit/placement/runtime events for browser/cloud/fog shell sessions.

These should interoperate instead of becoming parallel terminal truth systems.

Proposed scope

• Map CloudShell FOG audit events to TurtleTerm / SourceOS terminal receipt concepts.
• Decide whether CloudShell session IDs should map into SOURCEOS_TERMINAL_SESSION_ID when TurtleTerm is used as a local/agent surface.
• Define shared fields for actor, workspace, policy bundle, execution domain, command digest, and placement metadata.
• Add a small docs/integration/turtleterm.md or equivalent profile.
• Avoid duplicating receipt schema authority if TurtleTerm / SourceOS terminal contracts already own it.

Acceptance criteria

• CloudShell FOG has a documented TurtleTerm integration profile.
• The profile states which side owns which schema.
• No duplicate terminal receipt contract is invented in CloudShell FOG if TurtleTerm already owns it.