docs: add CloudShell FOG integration profile (current-main draft)

[mdheller]

Summary

Adds the TurtleTerm-side CloudShell FOG integration profile and receipt-context smoke test on a fresh branch from current main.

Why this replaces PR #3

The earlier PR #3 branch diverged heavily from main while upstream added TurtleTerm CloudFog, Superconscious, and Agent Machine bridge surfaces. This replacement branch starts from current main and replays only the integration artifacts plus the minimal current-main-safe fixes proven by CI triage.

Included

• docs/integration/cloudshell-fog.md
• assets/sourceos/tests/test_cloudshell_fog_receipt_context.py
• sibling-path resolution for bridge wrappers that invoke turtle-agentctl
• generated RPM builder fix so %install invokes the staging helper through bash

Integration scope

This PR documents and validates:

• CloudShell FOG session/audit correlation
• TurtleTerm ownership of terminal receipt semantics
• SOURCEOS_* environment propagation from CloudShell context
• receipt context preservation for session, workspace, actor, policy bundle, and execution domain

Follow-up tracking

Remaining repo-wide checks should stay tracked separately if they still fail:

• native Linux package verification: Stabilize native package build verification for RPM/Debian/Arch #7
• cargo-audit posture: Classify and remediate cargo-audit findings #8
• Homebrew install-from-HEAD validation: Stabilize Homebrew install-from-HEAD validation #9

[mdheller]

Capture update: superseded by #19.

#19 replayed the CloudShell FOG integration content onto current main and merged as d16e2fe04a904053ec71c1e8cad3b2e4e89c7d7e.

Captured:

• docs/integration/cloudshell-fog.md
• assets/sourceos/tests/test_cloudshell_fog_receipt_context.py
• generated RPM builder staging helper invocation through bash
• Linux package-layout staging helper invocation through bash
• Homebrew formula status CLI assertion alignment

Validation observed on #19 head c1c436332ed0dc38658ad679bda4a7e4c7d1ffa4:

• Trust Surface: success
• TurtleTerm Script Checks: success
• TurtleTerm Linux Packaging: success
• verify-pages: success
• TurtleTerm Security Checks: success
• TurtleTerm Homebrew Validation: success

Content status: captured. This draft can be closed as superseded.