CREATE TABLE fleet_firmware (
 id uuid PRIMARY KEY DEFAULT gen_random_uuid(), tenant_id uuid NOT NULL REFERENCES tenant(id),
 version_code bigint GENERATED ALWAYS AS IDENTITY UNIQUE,
 model text NOT NULL, version text NOT NULL, release_notes text NOT NULL DEFAULT '',
 size bigint NOT NULL CHECK(size > 0 AND size <= 33554432), sha256 text NOT NULL,
 object_ref text NOT NULL UNIQUE, status text NOT NULL DEFAULT 'UPLOADING' CHECK(status IN ('UPLOADING','READY')),
 created_at timestamptz NOT NULL DEFAULT now(), UNIQUE(tenant_id,model,version)
);
CREATE INDEX fleet_firmware_latest ON fleet_firmware(tenant_id,model,version_code DESC) WHERE status='READY';
CREATE TABLE fleet_presence (
 device_id uuid PRIMARY KEY REFERENCES device(id), password_hash bytea NOT NULL,
 connection_id uuid, connected boolean NOT NULL DEFAULT false, last_seen_at timestamptz,
 firmware_version text NOT NULL DEFAULT '', version_code bigint NOT NULL DEFAULT 0 CHECK(version_code>=0),
 ota_supported boolean NOT NULL DEFAULT false
);
CREATE TABLE fleet_ota (
 id uuid PRIMARY KEY DEFAULT gen_random_uuid(), device_id uuid NOT NULL REFERENCES device(id),
 release_id uuid NOT NULL REFERENCES fleet_firmware(id), request_id uuid NOT NULL UNIQUE,
 status text NOT NULL DEFAULT 'pending' CHECK(status IN ('pending','accepted','success','failed','timeout')),
 message text NOT NULL DEFAULT '', created_at timestamptz NOT NULL DEFAULT now(), updated_at timestamptz NOT NULL DEFAULT now()
);
CREATE UNIQUE INDEX fleet_ota_active ON fleet_ota(device_id) WHERE status IN ('pending','accepted');