Get Public Kol Similar

Public Related-Profiles roster — no auth required.

Drives the "Related Profiles" section on /k/{username}. Returns limit neighbour creators (default 8, max 20) selected from the same platform within a follower-count band around the seed.

Returns 404 with the same body as the dossier route when the seed doesn't exist or isn't public-eligible, so neither case is probe- able. 429 on rate limit, sharing the bucket with the dossier route (same IP, same window) — the frontend usually fetches both on a single page load so they collectively count toward the same quota.

Route ordering note: /kols/{username}/similar and /kols/{username} are different paths in FastAPI's router — the trailing segment disambiguates. Declaration order doesn't matter for correctness; we place /similar first purely for file readability (most-specific path first).