Remove what is about deploying behind Gitea (closes #209)

Delete the Gitea compose setup, its document, its two scripts and their
make targets. Documents and tests no longer use Gitea as the example
deployment. The Core Rule Set exclusions for Gitea's false positives in
internal/waf stay, with their comments and tests.

Model: opus-5-5

EVALUATION.md

@@ -153,15 +153,15 @@ Closest existing options, and why each still falls short:
     - What it is: a single-binary reverse proxy that makes browsers solve a
       proof-of-work challenge before passing them to `TARGET`. Aimed at
       scrapers, which is likely a large share of unwanted traffic on a public
-      gitea.
+      code forge.
     - Covers: R10 well (one container, env vars for listener, target,
       difficulty, cookies). Policy rules can match on path, user agent, headers,
       IP ranges, and with the vendor's hosted data service also AS number and
       country, and can weigh a request toward a harder challenge.
     - Misses: R1, R3, R4, R5, R6, R9. Bot policy needs a YAML file, not env
       vars. AS number and country matching depend on the vendor's hosted
-      service. Breaks non-browser clients unless paths are exempted; for gitea,
-      git-over-HTTP and API paths must be allowed through by rule.
+      service. Breaks non-browser clients unless paths are exempted; for a code
+      forge, git-over-HTTP and API paths must be allowed through by rule.
     - Maturity: very active, widely deployed on code forges since 2025.
     - Value here: complementary. It can be chained (traefik, then the sidecar,
       then Anubis, then the app) if challenge pages are wanted.