SPEC rework after review: each requirement once, gitea notes to docs/

Every requirement is stated once, where it belongs, and linked from
elsewhere. The notes on gitea move to docs/gitea.md, which
script/gitea-requests points at. The list of settings that take off
is exact, the non-goal that contradicted the planned item is gone,
and the sentences the review named are split or reordered. The
package comments in internal/waf and internal/anomaly point at the
renamed sections.

Model: fable-5-1

script/gitea-requests

@@ -2,11 +2,12 @@
 # script/gitea-requests: build the image and run gitea 1.27.3 behind it,
 # with every setting of smallwebwaf at its default but SWWAF_UPSTREAM_URL,
 # which names gitea's container. Then send through it the gitea requests
-# that reading gitea's source found the Core Rule Set refuses, and a short
-# sample of gitea's ordinary use: signing in, pages of files and commits,
-# a diff, the API, a push, clone and fetch over HTTP, and two container
-# image pushes. Last, print each request smallwebwaf logged, with what it
-# did with it and the ids of the Core Rule Set's rules that matched it.
+# that reading gitea's source found the Core Rule Set refuses, which
+# docs/gitea.md records, and a short sample of gitea's ordinary use:
+# signing in, pages of files and commits, a diff, the API, a push, clone
+# and fetch over HTTP, and two container image pushes. Last, print each
+# request smallwebwaf logged, with what it did with it and the ids of the
+# Core Rule Set's rules that matched it.
 # Every request comes from one client, docker's gateway, so more than
 # SWWAF_ERROR_BURST_THRESHOLD, 30, refusals in a minute would ban it, and
 # the requests after would show as banned. The containers, the network,