[Coder] Schema update

[ariga-bot]

Add a B-tree index on audit_logs(resource_type, resource_id) to speed up lookups for audit entries related to a specific resource (non-destructive, no data model change).

[github-actions]

atlas migrate lint on dirs/coder/migrations

Status	Step	Result
	1 new migration file detected	20260415153140.sql
	ERD and visual diff generated	View Visualization
	Analyze 20260415153140.sql 1 reports were found in analysis	Concurrent index violations detected Creating the index "idx_audit_logs_resource_type_id" non-concurrently acquires a SHARE lock on table "audit_logs", blocking writes but allowing reads during the operation (PG101)
Read the full linting report on Atlas Cloud