Get distinct parameters
Returns distinct values for common analysis parameters such as brands, categories, personas.
Personas come back twice. persona_ids holds the distinct ids of the personas the workspace’s analyses are
linked to — resolve them to profiles with GET …/personas?ids=….
personas holds the distinct values of the legacy display field, which means it can contain both free-text
labels and persona ids as strings: an analysis created from the persona library mirrors its ids into that
field. Build a display list by parsing each entry as a UUID — resolve the ones that parse through /personas
and show the rest as-is — or build the list from persona_ids alone and ignore personas. The two lists are
computed independently and have no positional relationship: an analysis predating persona records contributes
to personas only.