Harden live RAVEL Fabric operation - #13

Summary

• add a bounded long-running RAVEL consumer for the persistent Fabric controller
• constrain precompiled RAVEL probes to the producing OS/architecture so Linux artifacts cannot be placed on Windows workers
• harden detached submission metadata, result identity binding, health checks, and restart behavior
• add a live Fabric doctor Forge workflow and correct the standard controller socket path
• make source-checkout pytest collection reliable and make the Forge integration fixture writable without mutating the sibling Forge checkout

Validation

• python3 -m pytest -q: 92 passed, 29 subtests passed
• cargo test --workspace: passed
• focused persistent/agent/Forge suite: 10 passed
• Ruff and git diff --check: passed
• live ravel_fabric_agent.py doctor: PASS against Fabric 0.2.0a30; fabric-worker-01 is the eligible Linux/x86_64 worker

Authority boundary

RAVEL remains a consumer of Fabric execution evidence. This does not grant RAVEL fleet ownership, evaluator authority, selection authority, or promotion authority.

Live bootstrap validation

• persistent controller health: PASS on Fabric 0.2.0a30
• eligible artifact host: fabric-worker-01 (os:linux, arch:x86_64)
• branching work sha256:83e2a741b75bc1fcec1775ed896b009dfc5803497cf9eabd7f11514e913cb1e3: COMPLETED / PASS
• ring work sha256:c1acd21aacbe62ce951d86eb072d62731159e0deb3130464436b0b9fb24ff557: COMPLETED / PASS
• restart/bootstrap check: no duplicate work submitted; retained reports remain development-only evidence
• GitHub Actions: Python 3.11/3.12/3.13, Rust foundation, and RAVEL 0.6 C matrix all pass