Write SQL for first share and closest collaborator

You are given event data about users viewing design files. Assume the following tables: - `files(file_id, creator_id)` - `creator_id` is a VARCHAR user identifier. - `file_views(file_id, user_id, viewed_at)` - `user_id` is an INTEGER user identifier. - Each row means `user_id` viewed `file_id` at time `viewed_at`. A “share” is inferred when **someone other than the creator** views a file. 1) **First share time per creator** Write a SQL query that returns, for each creator, the first time they ever shared a file they created (i.e., the earliest `viewed_at` where a non-creator viewed one of their files). Output columns: - `creator_id` - `first_shared_at` Notes: - A creator viewing their own file should not count. - `creator_id` (VARCHAR) and `user_id` (INTEGER) are different types; handle casting appropriately. 2) **Closest collaborator model** For each file, define the “first person it was shared with” as the **earliest non-creator viewer** of that file (based on `viewed_at`). Build a query/model that, for each creator, finds their **closest collaborator**, defined as the user who was the “first person shared with” for the creator’s files **the most times**. Output columns: - `creator_id` - `closest_collaborator_user_id` - `collaborator_value` (the number of files for which this collaborator was the first non-creator viewer) Tie-breaking: if multiple collaborators have the same `collaborator_value`, choose the one with the earliest first-share timestamp across those tied records (and if still tied, the smallest user id).