Hide Program ids from generated issue briefs

[yvette-carlisle]

Summary

• remove internal Execution Program and node id lines from generated Linear issue briefs
• keep private Program/node mappings in runtime state while validating they do not leak into generated titles/descriptions
• update loop/runtime docs and runbook language for the public/private boundary

Validation

• cargo test -p decodex program_intake --all-features
• cargo make docs-check
• cargo make fmt-check
• cargo make check-rust
• git diff --check

Authority: XY-971