chore(pylon): disable inherited upstream workflows

[rynfar]

Problem

The Pylon product branch still carried Prime's Linear ticket gate and release publication workflow even though Pylon tracks work in GitHub issues and has not defined fork release ownership. Mirrored upstream automation must not become Pylon policy by inheritance.

Resolution

• Remove the Linear ticket workflow from pylon.
• Remove the inherited binary/package release workflow from pylon while release naming, provenance, signing, storage, and channels remain undefined.
• Record the workflows explicitly retained after audit.
• Document the singleton-safe branch policy: PRs, strict checks, conversation resolution, and admin enforcement with zero formal approvals until a second eligible reviewer exists.
• Record the intentional omissions so future upstream merges preserve them.

The exact upstream mirror on main remains unchanged.

Validation

• npm run check
• git diff --check
• Repository release secrets, variables, environments, and releases are empty
• Independent operations and release audits found no blocker in the workflow deletions

Refs #1

Model: OpenAI Codex GPT-5.6
Harness: Prime Agent

[rynfar]

The first hosted run was not merged: Test (coding-agent 1/3) reported a Vitest environment-teardown import race after all 1,453 tests in the shard had passed. The PR changes only workflow/docs policy and do not touch the cited highlighter or test code. Rerunning the failed job and aggregate check; merge remains gated on a clean rerun.