[Coder] Schema update

[ariga-bot]

Backward-incompatible change: renamed column last_used to last_used_at in public.api_keys. Applications referencing api_keys.last_used will break until updated.

[github-actions]

atlas migrate lint on dirs/coder/migrations

Status	Step	Result
	1 new migration file detected	20260715153434.sql
	ERD and visual diff generated	View Visualization
	Analyze 20260715153434.sql 2 reports were found in analysis	Destructive changes detected Dropping non-virtual column "last_used" (DS103) Data dependent changes detected Adding a non-nullable "timestamptz" column "last_used_at" will fail in case table "api_keys" is not empty (MF103)
Read the full linting report on Atlas Cloud

[github-actions]

Caution

destructive changes detected
Dropping non-virtual column "last_used" DS103

Add a pre-migration check to ensure column "last_used" is NULL before dropping it

Suggested change

	-- Modify "api_keys" table
	ALTER TABLE "api_keys" DROP CONSTRAINT "api_keys_expires_at_not_before_last_used", ADD CONSTRAINT "api_keys_expires_at_not_before_last_used" CHECK (expires_at >= last_used_at), DROP CONSTRAINT "api_keys_last_used_not_before_sentinel", ADD CONSTRAINT "api_keys_last_used_not_before_sentinel" CHECK (last_used_at >= '0001-01-01 00:00:00+00'::timestamp with time zone), DROP COLUMN "last_used", ADD COLUMN "last_used_at" timestamptz NOT NULL;
	-- atlas:txtar
	-- checks/destructive.sql --
	-- atlas:assert DS103
	SELECT NOT EXISTS (SELECT 1 FROM "public"."api_keys" WHERE "last_used" IS NOT NULL) AS "is_empty";
	-- migration.sql --
	-- Modify "api_keys" table
	ALTER TABLE "api_keys" DROP CONSTRAINT "api_keys_expires_at_not_before_last_used", ADD CONSTRAINT "api_keys_expires_at_not_before_last_used" CHECK (expires_at >= last_used_at), DROP CONSTRAINT "api_keys_last_used_not_before_sentinel", ADD CONSTRAINT "api_keys_last_used_not_before_sentinel" CHECK (last_used_at >= '0001-01-01 00:00:00+00'::timestamp with time zone), DROP COLUMN "last_used", ADD COLUMN "last_used_at" timestamptz NOT NULL;

Ensure to run atlas migrate hash --dir "file://dirs/coder/migrations" after applying the suggested changes.