feat: declare the SNMP health OIDs instead of collecting them (0.2.0)

The driver no longer collects over SNMP. SNMP_HEALTH_PROFILE states
where the switch publishes uptime (TimeTicks), CPU and memory (tables
with one row per stack unit, first row as before); the application
polls and computes (napalm-device-types docs/STRUCTURE.md).

Interface counters now come from the 64-bit ifXTable where the switch
has it, as the application reads them for every device.

tests/unit/test_snmp_profile.py

@@ -0,0 +1,25 @@
+"""The switch's SNMP health OIDs, declared as data (napalm-device-types docs/STRUCTURE.md).
+
+The driver does not collect over SNMP; the application polls with this profile.
+"""
+
+from napalm_tplink_jetstream.tplink_jetstream import TPLinkJetstreamDriver
+
+PROFILE = TPLinkJetstreamDriver.SNMP_HEALTH_PROFILE
+
+
+def test_the_driver_does_not_collect_itself():
+    assert "get_health_metrics" not in vars(TPLinkJetstreamDriver)
+
+
+def test_uptime_in_timeticks_from_the_tp_link_mib():
+    # swt-l2-3-38 answered 129434122 (2026-10-16): TimeTicks, about 15 days.
+    assert PROFILE["uptime"] == {"oids": ["1.3.6.1.4.1.11863.6.1.1.9.0"]}
+
+
+def test_cpu_and_memory_per_unit_take_the_first_row():
+    # One row per stack unit; a single switch answers row 1 only.
+    assert PROFILE["cpu"] == {"table": "1.3.6.1.4.1.11863.6.4.1.1.1.1.3", "fold": "first"}
+    assert PROFILE["memory"] == {
+        "percent": {"table": "1.3.6.1.4.1.11863.6.4.1.2.1.1.2", "fold": "first"}
+    }