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Cover was named in the Series entry but never defined, and the gap is what #47 is: nothing said whether a Cover is an address on a Site or an image a Reader's browser can actually display. Kagane proved they are not the same thing. The ADR records the decision that follows — the backend fetches, stores and serves every Site's cover bytes — along with the alternatives that were rejected and the two knowing relaxations: destination-class control instead of the host allowlist fetchableSeriesURL sets as precedent, and a public cover route where the kagane proxy is session-gated.