docs(rss-bridge): #51 was closed, and the cause was never identified (2.1.1)

PR #124 merged at 12:25 and the maintainer closed #51 one second later, on
the strength of that round's green install-test. Three statements that
merged with #124 are stale as a result, and they are stale in the
direction that matters - they describe a failing test and an open issue:

  - rss-bridge/templates/rss-bridge.httproute.yaml and values.yaml said
    the install-test "fails on the Gitea runner (#51)", in the present
    tense, and values.yaml added "and that test is still red".
  - ci/httproute/rss-bridge.yaml said "#51 is not closed on the strength
    of a colour", which was true when written and is now the opposite of
    what happened.

Replaced with what is actually known, and the emphasis moved to the part
that outlives the colour: the test went green on a render byte-identical
to main, which rules the chart out and leaves the runner - and THE CAUSE
WAS NEVER IDENTIFIED. The diagnostic programme in #51 (docker info for
userns and the dind configuration, the same image in a local k3d without
remapping) was not executed. So a recurrence is a fresh finding rather
than a known quirk, and the overlay comment now says so where whoever
sees the red will be reading.

Also carries the wording change that was already on this branch when
#124 merged: the reproduced green is phrased as "every run of that branch
since" rather than pinned to a count, because each commit recording the
count invalidated it - a third green arrived with the push after "two".

Patch bump, per the rule #40 was argued on: a comment in a chart
directory is still a change to that chart, so it is a patch plus a
publish. No template output changes - the render for the fixture values
is byte-identical to the pre-#124 main, which the tests re-confirm.

rss-bridge/Chart.yaml

@@ -5,7 +5,7 @@ icon: https://raw.githubusercontent.com/RSS-Bridge/rss-bridge/master/static/logo
 
 type: application
 
-version: 2.1.0+up2026.09.30
+version: 2.1.1+up2026.09.30
 appVersion: "2026-09-30"
 
 maintainers: