docs(prod): node 1's DIMMs are not a matched pair

Surfaced by the new node_health DIMM reporting, unrelated to the memattr bug and NOT a fault:
DIMM1 is a Micron 8ATF2G64HZ-3G2E1 (DDR4-3200), DIMM3 a Micron 16ATF2G64HZ-2G6E1 (DDR4-2667).
Both 16 GB so capacity is right, but different rank organisation and rated speed mean the pair
runs at the slower 2667.

Recorded in §0 where the symmetry decision gets made, because §2 requires the three nodes to end
up with identical layouts and the previous '2x16 GB Micron' note hid the mismatch.

Serves: R-ENV-03. Task: T-7.1.

infra/PROD-PROVISIONING.md

@@ -35,6 +35,12 @@ Fill a row per node as it lands. Node 1 is as-found on 2026-08-31.
 | `/dev/kvm` | present | present | |
 | Serial | MXL1052NGN | MXL0073949 | |
 
+**Node 1's DIMMs are also not a matched pair** (surfaced 2026-09-01 by the new health check;
+unrelated to §0b and **not a fault**): `DIMM1` is a Micron **8**ATF2G64HZ-**3G2**E1 (DDR4-**3200**),
+`DIMM3` a Micron **16**ATF2G64HZ-**2G6**E1 (DDR4-**2667**). Both are 16 GB so capacity is correct,
+but they differ in rank organisation and rated speed, so the pair runs at the slower 2667. Recorded
+only because §2 requires the three nodes to end up symmetric, and "2×16 GB Micron" hid the mismatch.
+
 **The nodes are NOT hardware-symmetric.** Node 1 has a ~2011 SATA SSD with real wear; node 2 has a
 healthy modern NVMe. §2 requires an identical disk layout across all three because Longhorn replica
 placement assumes symmetry — so this is a live input to the disk decision, not a footnote. Node 2's