The Core Rule Set, run by Coraza, on each request's method, URL and headers (closes #25)

Coraza v3.8.1 runs the Core Rule Set 4.25.0 (coraza-coreruleset v4.25.0)
after the rule files, with the six changes and the default
SWWAF_WAF_DISABLED_RULES that SPEC.md gives; no body, no response. The
parameter names in the third and fourth changes are matched in any case,
as Coraza does. SWWAF_WAF_DISABLED_RULES refuses 900000 to 900999,
smallwebwaf's own rules. A request with more than 1000 query parameters
adds 5 (rule 900300). In block mode a match is refused with 403, an
offence counted toward the error burst; in detect mode it is let
through. Both log waf_rule_ids, waf_score and duration_waf, raise
waf_block, and count smallwebwaf_waf_matches_total.

Judgement call: waf_block is raised in block mode too.
Deviation: no engine-error path; with no body read, Coraza cannot fail.

Model: opus-5-5

SPEC.md

@@ -618,10 +618,12 @@ The settings, by group:
           `|cat /etc/passwd`, `wget http://…` and `nc -e /bin/sh …`, and
           `file:///etc/passwd`, pass as well. Path traversal (`../`), SQL and
           script injection and PHP, Java and Node.js code are still refused
-          there, and every other parameter keeps all three rules. An app that
-          uses one of these parameters as a file on the server, or passes it to
-          a shell, gets no help from the three rules there (see "Risks the
-          design has to handle").
+          there, and every other parameter keeps all three rules. These names,
+          and `redirect_uri` in the change before, are matched without regard to
+          case, as Coraza matches them, so `Path` or `PATH` is treated as
+          `path`. An app that uses one of these parameters as a file on the
+          server, or passes it to a shell, gets no help from the three rules
+          there (see "Risks the design has to handle").
         - The Core Rule Set reads the request without the `gitea_flash` and
           `redirect_to` cookies, and does not check `Referer` for a Unix command
           given without arguments (932340) or for Java starting a process