Tags every fact-claim in a document inline as either `[validated, {source}]` or `[assumption, retire-by {milestone}]`, so a reader can see at a glance which sentences rest on evidence and which rest on reasoning, and what would convert each assumption into knowledge. Use when a brief mixes cited facts with reasoned-from-priors numbers — "mark which claims are sourced and which are assumptions", "tag the provenance of these claims", "which numbers here are actually validated?", "add validated/assumption tags to this draft". Not for verifying whether a number is correct (use `grounded-fact-check`) or for corroborating one claim across sources (use `triangulate-sources`).
