feat(db): add is_default column to ssh_keys with per-org uniqueness constraint

Author: raghavyuva

drizzle/0039_add_ssh_key_is_default.sql

@@ -0,0 +1,9 @@
+ALTER TABLE "ssh_keys" ADD COLUMN "is_default" boolean DEFAULT false NOT NULL;--> statement-breakpoint
+UPDATE "ssh_keys" SET "is_default" = true
+WHERE "id" IN (
+  SELECT DISTINCT ON ("organization_id") "id"
+  FROM "ssh_keys"
+  WHERE "deleted_at" IS NULL AND "is_active" = true
+  ORDER BY "organization_id", "created_at" DESC, "id" DESC
+);--> statement-breakpoint
+CREATE UNIQUE INDEX "ssh_keys_one_default_per_org" ON "ssh_keys" USING btree ("organization_id") WHERE is_default = true AND deleted_at IS NULL;