Function complete 

pub async fn complete(
    pool: &PgPool,
    vault: &Vault,
    actor: &Actor,
    id: Uuid,
    revision_id: Option<Uuid>,
) -> AppResult<Upload>

Verifies a fully received upload (size, announced SHA-256), moves it into the vault and classifies it like a regular upload, with the session’s base and folder. Nothing is registered in the database yet – pass the result to files::attach / files::check_in and then call forget.

Calling it again after a failed attach (e.g. the database was briefly unavailable) reuses the stored content – nothing has to be re-sent. Content that fails verification resets the session to offset 0.

Invariants

• Permission: the actor’s own session (404 otherwise); revision_id, when given, must be the session’s revision (400). complete_in applies the Scope rules: NewItem accepts only sessions without a revision, Revision(id) only that revision, Any whatever the session allows.
• Locks: the session row (FOR UPDATE).
• Data: all bytes must have arrived (409 otherwise). Size and announced SHA-256 are verified; a mismatch (400) or lost staging data (409) resets the session to offset 0 and commits that reset. The verified hash is recorded on the session, so a repeated call reuses the stored content.
• Steps: the staged file moves into the vault before the transaction commits; a crash in between is recovered when the announced SHA-256 is in the vault. The session row stays until forget or abort.
• Audit, notifications, webhooks: none; nothing is registered in the database as a file.