docs: the stale-Good quality contract, stated once (R3-02)

docs/Raw.md

@@ -123,6 +123,17 @@ the full design. Highlights:
   rejects an A→B→A oscillation loop naming the members. Compile is not hard-gated (VirtualTag
   parity); a runtime compile/throw/timeout lands as Bad quality + a `script-logs` entry.
 
+## Quality: a raw tag's node when its driver stops communicating
+
+A raw tag's node — and every UNS mirror of it — goes **`BadNoCommunication` with its last value
+retained** when the owning driver is declared comms-lost, and clears when the driver re-publishes. It is
+never cleared by the server on reconnect: recovery is a value, never an assumption. The rule and the
+seams that implement it are stated once in
+[`docs/DriverLifecycle.md` §"The quality contract"](DriverLifecycle.md#the-quality-contract).
+
+Calc tags authored here inherit the same rule from their inputs — see
+[`docs/drivers/Calculation.md` §"Input quality"](drivers/Calculation.md#input-quality).
+
 ## Retirement note
 
 The routed `/clusters/{id}/drivers` driver-authoring flow (`DriverTypePicker`,