Say which bytes the byte limits count, and what passing one does (closes #203)

Documents only. The byte limits and byte anomaly thresholds count body
bytes, as SWW_BYTES_COUNT chooses them, with WebSocket traffic each way,
once a response has ended; the request that passes a limit is not cut
off and the client is banned. README.md, SPEC.md and docs/ now say so,
and no longer call a response's bytes the request's. Also made plain:
rate limits and their exemptions, the refusal threshold,
SWRP_MAX_REQUEST_TIME_MS, SWRP_MAX_RESPONSE_SIZE, SWW_LOOKUP_SOURCE,
SWW_LIMIT_BAN_REPEAT_WINDOW, the metrics' byte series, and the SPEC.md
claim about answering within SWRP_TIMEOUT_MS. EVALUATION.md is audited
too; its survey facts and date are unchanged.

Model: fable-5-1 (first audit); opus-5-5 (rework)

docs/request-log.md

@@ -144,20 +144,22 @@ Every one of these lines has:
   included. It is left out when rate limiting did not count the request. It
   holds:
     - `minute`, `hour` and `day`: requests;
-    - `minute_bytes`, `hour_bytes` and `day_bytes`: bytes.
+    - `minute_bytes`, `hour_bytes` and `day_bytes`: the body bytes
+      `SWW_BYTES_COUNT` names, in that window.
 
     A count can have a fraction (see "Counting method" in
-    [`SPEC.md`](../SPEC.md)). The bytes of an allowed request are counted when
-    its report comes. So on the `decision` line, the bytes are without this
-    request's.
+    [`SPEC.md`](../SPEC.md)). The bytes counted for an allowed request and its
+    response are added when its report comes. So on the `decision` line, the
+    three byte totals leave them out.
 
 - `limit_hit`: the limit broken:
     - `minute`, `hour` or `day` for a rate limit;
     - `minute_bytes`, `hour_bytes` or `day_bytes` for a byte limit;
     - `error_burst`.
 
-    A request whose bytes broke a limit was passed on whole, so its `action`
-    stays `forward`. Only its `report` line gives that limit.
+    When the bytes counted for a request and its response break a limit, the
+    request has been passed on whole, so its `action` stays `forward`. Only its
+    `report` line gives that limit.
 
 - `rule_ids`: the rule file rules that matched, in order, up to the one that
   refused.