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

sneak asked for every document to be audited for sentences that do not say what they mean. The byte limits now say which bytes count (response bodies, request bodies or both, as `SWW_BYTES_COUNT` says, WebSocket traffic included) and what passing one does. Other unclear or false sentences in `README.md`, `SPEC.md`, `EVALUATION.md` and `docs/` are rewritten.

Documents only. `REPO_POLICIES.md` is shared policy text and stayed out.

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

docs/state-files.md

@@ -61,7 +61,7 @@ since it was first seen:
 - the first and last time seen;
 - the AS number, AS name and country last looked up, and when;
 - total requests, and how many were forwarded and how many refused;
-- bytes in each direction;
+- body bytes of its requests, and of the responses it was sent;
 - responses by status class;
 - offences by kind: `limit`, `attack`, `rule_blocked` and `waf_blocked`. A file
   may also hold `token_refused`, which is kept, and which nothing adds to.