Fence the attacker-controllable maintainer-comment excerpt on a FetchedPR
for agent-facing serialization (#1420). Applied at the serialization
boundary (daily/startup --json via deduplicateDigest, MCP PR resources)
rather than at fetch time: extractMaintainerActionHints parses the RAW
body inside the pipeline, and human surfaces (dashboard SPA, CLI text
mode) must not render fence markup. Returns a copy; never mutates.
Fence the attacker-controllable maintainer-comment excerpt on a FetchedPR for agent-facing serialization (#1420). Applied at the serialization boundary (daily/startup --json via deduplicateDigest, MCP PR resources) rather than at fetch time: extractMaintainerActionHints parses the RAW body inside the pipeline, and human surfaces (dashboard SPA, CLI text mode) must not render fence markup. Returns a copy; never mutates.