**New citation format: source-tagged with global numbering.** Reports can now render citations as `[arxiv-1]`, `[openai.com-2]`, `[arxiv-3]` — the source tag identifies what kind of source each citation is (short URLClassifier tag for known academic sources, cleaned domain for generic web URLs, or the collection name for local RAG/library hits, e.g. `[my-papers-4]`), while the number stays the original global counter so labels never collide and inline citations match the bibliography order. Opt in via `report.citation_format → "Source-tagged with global numbering"`; the existing default remains `Numbers with hyperlinks [1]`.
