fix(freesailarr): redirect the bare /qbittorrent prefix in Gateway mode

qBittorrent has no base-path setting, so the chart serves it under a prefix
and strips that prefix before the request reaches it. For the slashed form
that is correct. For the BARE form - /qbittorrent, no trailing slash - the
request is rewritten to "/" and qBittorrent answers 200 with its login page,
while the browser's document URL keeps the prefixless form. Every relative
link in that page therefore resolves against the host root, and on the shared
host the root is seerr: the login form comes up unstyled and does nothing
while a different application answers its assets and XHRs. Nothing reports an
error at any level.

The shared-domain HTTPRoute now carries a second rule for qBittorrent: an
Exact match on qbittorrent.ingress.path with a RequestRedirect filter that
replaces the full path with the slashed form, statusCode 301. The Gateway API
ranks an Exact path match above every prefix match, so it wins over both
qBittorrent's own PathPrefix rule and seerr's "/" wherever it is emitted - the
rules' length-descending order stays a rendering convention. 301 rather than
308 because only 301 and 302 are Core in that API; an Extended value an
implementation declines makes it set Accepted=False on the WHOLE route, which
would take the four neighbouring apps' routing down with it, and that would
also contradict decision 1 of Gitea #114. statusCode is written out because it
defaults to 302. The rule is guarded on the app being qbittorrent and its path
not being "/", and it reads the path from the value, never a literal.

The INGRESS BRANCH IS UNCHANGED, deliberately. The remedy there is an
nginx configuration-snippet annotation, and the chart cannot ship it: snippets
are ignored unless the controller runs with allow-snippet-annotations=true,
off by default since ingress-nginx 1.9 and only switched on by accepting
annotation risk level "Critical". A shipped annotation would be a silent no-op
on every cluster keeping the default. The working snippet, that price, and why
a third Ingress object with pathType: Exact is not a substitute - buildLocation
in ingress-nginx controller-v1.14.5 returns a regex location in its
enforceRegex branch before reaching the PathTypeExact branch, and enforceRegex
is computed once per nginx server over every location of the hostname, one of
which carries rewrite-target - are all written out in values.yaml instead.

ci/run-httproute-match-test.sh gains a third assertion, per HTTPRoute object:
a rule stripping a prefix with ReplacePrefixMatch requires a rule in the same
route matching that path Exactly and carrying a RequestRedirect filter. This
is what stops the gap reappearing; bulwark is the second rewrite-target chart
and meets the same check when group 3 of Gitea #114 lands. 37 assertions over
15 charts, up from 36. Both fail paths were exercised: the rule deleted, and
the redirect pointed at a path other than the one stripped.

Minor and not major: with the Ingress branch untouched and httpRoute.enabled
defaulting to false, no existing release's render changes by a byte and no
value becomes required. Shown by an empty helm template diff against
origin/main in both Ingress shapes, shared-domain and per-app hosts.

Fixes #118

README.md

@@ -163,22 +163,25 @@ Measured: 30 charts, **5 selectors verified in ~14 s**, no cluster. The fail pat
 
 ### HTTPRoute render test (all charts, every PR)
 
-`ci/run-httproute-match-test.sh [chart …]` (no argument = all charts) renders every chart with the same fixtures the install-test uses and checks every `HTTPRoute` in the result against the `Service` objects of that **same** render. Introduced with the Gateway-API pilot (Gitea #114); two failure modes, both silent:
+`ci/run-httproute-match-test.sh [chart …]` (no argument = all charts) renders every chart with the same fixtures the install-test uses and checks every `HTTPRoute` in the result against the `Service` objects of that **same** render. Introduced with the Gateway-API pilot (Gitea #114); three failure modes, all silent:
 
 | Finding | What it does | Who notices today |
 |---|---|---|
 | `parentRefs` empty | the route attaches to **no** Gateway: created, schema-valid, rejected by nobody, and it routes nothing | nobody — no event, no condition, the only symptom is a hostname that does not answer |
 | `backendRefs` naming a Service or a port that does not exist | the reference is resolved **by name** at runtime and validated by nothing | nobody in CI — `ResolvedRefs: False` lands in a route status that only a Gateway controller writes, and none runs here |
+| a prefix stripped with `ReplacePrefixMatch` while the same route carries no `Exact` match on that prefix with a `RequestRedirect` filter (Gitea #118) | the **slashless** form of the path is rewritten to `/` and answered **200** by the app, under a document URL that keeps the prefix off — so every relative link in that page resolves against the host root, which on a shared host is a *different* application | nobody — the app's own assets and XHRs are served by its neighbour, and the symptom is a half-working UI, not an error |
 
-**The real CRDs in the install-test do not close either gap**, which is the whole reason this job exists next to them: the Gateway-API schema happily accepts an empty `parentRefs` list and a `backendRefs` entry pointing at a Service that was never created. The CRDs prove the object is *well-formed*; this test proves it *points somewhere*. The port half is a genuine new exposure rather than a hypothetical: an Ingress backend references its Service port **by name**, while `backendRefs` takes a `PortNumber` and cannot, so the number in the route and the port in the Service are kept in step by hand from now on.
+**The real CRDs in the install-test close none of these gaps**, which is the whole reason this job exists next to them: the Gateway-API schema happily accepts an empty `parentRefs` list, a `backendRefs` entry pointing at a Service that was never created, and a prefix-stripping rewrite with no redirect beside it. The CRDs prove the object is *well-formed*; this test proves it *points somewhere*, and *somewhere right*. The port half is a genuine new exposure rather than a hypothetical: an Ingress backend references its Service port **by name**, while `backendRefs` takes a `PortNumber` and cannot, so the number in the route and the port in the Service are kept in step by hand from now on.
+
+The third check is a **pairing within one HTTPRoute object**, and the scope is deliberate: Gateway-API matching precedence is a property of a single route, so a redirect in a *different* route (a different hostname) says nothing about this one. Precedence also makes the pairing a question of existence rather than order — an `Exact` path match outranks every prefix match, so the redirect rule wins wherever it is emitted, and the rules' length-descending order stays a rendering convention. `freesailarr` is the first chart it applies to; `bulwark`, the second `rewrite-target` chart, meets the same check when group 3 of #114 lands, which is why the rule lives here and not in one chart's template.
 
 Three things to know before touching it:
 
 - **Helm is the YAML parser**, through `ci/yaml2json`, for the same reason as the selector-match test above — the runners have neither `pyyaml` nor `yq`, and a parser written in `awk` fails by reading nothing and reporting nothing.
-- **What is deliberately not checked**, named so the gaps are not mistaken for coverage. *That traffic flows* — no Gateway controller runs in CI and none will, so `Accepted: True` is not obtainable; that claim is simply not made anywhere in this pipeline. *Mutual exclusion with the Ingress* — each chart aborts its own render when `ingress.enabled` and `httpRoute.enabled` are both true, which is where it belongs: this test renders one configuration per chart, and a rule here would have to assume the switch is chart-global, which may not survive the multi-app charts of the sweep. *Cross-namespace and non-Service backends*, and a rule with no `backendRefs` at all (legal for a filter-only rule) — all three are **reported as "not checked", never counted as passing**.
+- **What is deliberately not checked**, named so the gaps are not mistaken for coverage. *That traffic flows* — no Gateway controller runs in CI and none will, so `Accepted: True` is not obtainable; that claim is simply not made anywhere in this pipeline. *That any redirect is ever served* — the pairing check proves the rendered **object** carries a `RequestRedirect` rule on the bare prefix and nothing more: whether an implementation honours the `statusCode` or declines it and fails the whole route is outside what a render can see. *Mutual exclusion with the Ingress* — each chart aborts its own render when `ingress.enabled` and `httpRoute.enabled` are both true, which is where it belongs: this test renders one configuration per chart, and a rule here would have to assume the switch is chart-global, which may not survive the multi-app charts of the sweep. *Cross-namespace and non-Service backends*, and a rule with no `backendRefs` at all (legal for a filter-only rule) — all three are **reported as "not checked", never counted as passing**. The redirect rule the pairing check demands is itself backend-less, so a chart that satisfies that check also earns one "not checked" line; both verdicts are correct at once.
 - **Two anti-vacuum guards**, because the convention ships `httpRoute.enabled: false` and this test would otherwise be green over nothing. `ci/httproute/<chart>.yaml` is a render-only overlay applied **last** whose one job is to put a chart into Gateway mode — and a chart that *has* one and still renders no route **fails**. On top of that the run fails if **no assertion at all** held anywhere. `cyberchef` is exercised through its ordinary install-test fixture (which installs in Gateway mode, see below), every other converted chart through its overlay. For a multi-app chart the overlay also has to enter every shape the template has: `ci/httproute/freesailarr.yaml` moves one app onto a host of its own so that the shared-host route *and* the per-app route are both rendered.
 
-Measured in CI (run 719, the pilot): **30 charts, 4 assertions held**, whole job 13 s including checkout and the Helm setup, no cluster. Group 1 took that to 20 assertions over 10 charts and group 2 to **36 over 15** — the sweep adds charts, not checks, so the job stays a render. The fail path was exercised rather than assumed: a Service renamed in the route, a port the Service does not expose, a port left out entirely, an emptied `parentRefs` with the chart's own guard disabled, an overlay that renders no route, and a run with zero assertions — each produced a `FAIL` naming both sides and a non-zero exit.
+Measured in CI (run 719, the pilot): **30 charts, 4 assertions held**, whole job 13 s including checkout and the Helm setup, no cluster. Group 1 took that to 20 assertions over 10 charts and group 2 to 36 over 15; the prefix/redirect pairing of Gitea #118 adds the first check since the pilot rather than a chart, which brings it to **37 over 15** — one assertion for `freesailarr`'s `/qbittorrent`, plus one more "not checked" line for the backend-less redirect rule it demands. The fail path was exercised rather than assumed: a Service renamed in the route, a port the Service does not expose, a port left out entirely, an emptied `parentRefs` with the chart's own guard disabled, an overlay that renders no route, a run with zero assertions, and — for the pairing — both the redirect rule deleted outright and the redirect pointed at a path other than the one stripped; each produced a `FAIL` naming both sides and a non-zero exit.
 
 ### Install-test (PR pipeline stage 2)
 
@@ -393,7 +396,7 @@ These guidelines are **binding for every current and future chart** in this repo
   - **CI**: either the chart's install-test fixture installs in Gateway mode, or it gets a render-only overlay at `ci/httproute/<chart>.yaml` — otherwise `ci/run-httproute-match-test.sh` is green over nothing for it, which that test fails on. An overlay for a multi-app chart has a second job: it must enter **every** shape the template has, or the branch nobody exercised is the one that breaks. `ci/httproute/freesailarr.yaml` gives one app a host of its own so both the shared-host route and the per-app route render.
 
   Reference implementation: `template-chart/templates/xxx.httproute.yaml`. Pilot: `cyberchef`. Group 1 — the charts rendering one Ingress with no behaviour-bearing annotation — followed: `bentopdf`, `garage`, `patchmon`, `rallly`, `searxng`, `sure`, `urlaubsverwaltung`, `voucher-vault`. Group 2 — the charts whose behaviour hangs off an nginx annotation — followed: `calibre-web-automated`, `outline`, `paperless-ngx`, `zipline` (all four `proxy-body-size`) and `freesailarr` (`rewrite-target`). That leaves **seven** charts: the six of group 3 — the special shapes (`homeassistant` is the documented ingress exception, `keycloak` and `bulwark` have two Ingresses each, `matrix-synapse` renders in a loop, `stalwart` renders per node group, `ytdlp-web-player` hangs off the oauth2-proxy subchart) — and `rss-bridge`, which is frozen for changes (#51) and is why #114 cannot be closed while #51 is open. `garage` was one of the named special cases and is done: it ships `ingress.enabled: false`, so both of its modes are off by default and its route is exercised by a render overlay rather than by the install-test, which keeps its Ingress. `paperless-ngx` was the one chart in the repository that still rendered its Ingress **unconditionally**; group 2 gave it an `ingress.enabled` switch defaulting to `true`, because without a second value path there is nothing for the mutual-exclusion abort to name and the `required()` on `clusterIssuer` would have kept demanding a value the Gateway mode does not use.
-- **Documented exception — freesailarr, and it extends to the Gateway mode**: the chart bundles several independently exposed apps in one pod, so it has **no** `ingress.domain` — and therefore **no `httpRoute.hostnames`** either, the only chart without that key. A chart-global list of hostnames could not say which of the ten apps it belonged to, so the hostnames stay where they already are, in `ingress.host` and `<app>.ingress.host`; both are read by both modes and neither is an Ingress switch. In Gateway mode the per-app shape renders one `HTTPRoute` per app (`<release>-<chart>-<app>-httproute`) and the shared shape exactly one (`<release>-<chart>-httproute`) with one rule per app — qBittorrent included, since its prefix-stripping rewrite is a per-rule filter there. It offers both shapes. By default each app carries its own `<app>.ingress.enabled` plus a required `<app>.ingress.host` (required only while that app's ingress is enabled and it is not on the shared domain) and renders its own Ingress object `<release>-<chart>-<app>-ingress` with its own TLS secret `tls-<release>-<chart>-<app>-ingress`. Setting the global `ingress.host` switches every app without a host of its own to the shared-domain shape under `<app>.ingress.path`; qBittorrent (no base path, needs a prefix-stripping rewrite) gets the extra object described above, and seerr as well as mediathekarr are pinned to `/` — mediathekarr because its UI links assets with root-absolute paths, which a rewrite cannot fix; with both of them on one shared host the duplicate-path guard fires and one of them needs a host of its own (its ingress is therefore off by default). `clusterIssuer`, `className` and `annotations` stay global defaults under `ingress.` and are overridable per app.
+- **Documented exception — freesailarr, and it extends to the Gateway mode**: the chart bundles several independently exposed apps in one pod, so it has **no** `ingress.domain` — and therefore **no `httpRoute.hostnames`** either, the only chart without that key. A chart-global list of hostnames could not say which of the ten apps it belonged to, so the hostnames stay where they already are, in `ingress.host` and `<app>.ingress.host`; both are read by both modes and neither is an Ingress switch. In Gateway mode the per-app shape renders one `HTTPRoute` per app (`<release>-<chart>-<app>-httproute`) and the shared shape exactly one (`<release>-<chart>-httproute`) with one rule per app — qBittorrent included, since its prefix-stripping rewrite is a per-rule filter there, and it is the one app contributing **two** rules: the rewrite plus a 301 from the bare, slashless prefix to the slashed form (Gitea #118). Without that redirect the slashless path is stripped to `/`, answered 200, and the page's relative links resolve to the root of the shared host — a different app. **The Ingress mode does not render it and cannot**: nginx offers only a `configuration-snippet` annotation, which is ignored unless the controller runs with `allow-snippet-annotations=true` (off by default since ingress-nginx 1.9, and it means accepting annotation risk level `Critical`), so the chart documents the snippet in `values.yaml` instead of shipping a no-op. It is the one place where the Gateway mode closes a gap rather than merely replacing machinery. It offers both shapes. By default each app carries its own `<app>.ingress.enabled` plus a required `<app>.ingress.host` (required only while that app's ingress is enabled and it is not on the shared domain) and renders its own Ingress object `<release>-<chart>-<app>-ingress` with its own TLS secret `tls-<release>-<chart>-<app>-ingress`. Setting the global `ingress.host` switches every app without a host of its own to the shared-domain shape under `<app>.ingress.path`; qBittorrent (no base path, needs a prefix-stripping rewrite) gets the extra object described above, and seerr as well as mediathekarr are pinned to `/` — mediathekarr because its UI links assets with root-absolute paths, which a rewrite cannot fix; with both of them on one shared host the duplicate-path guard fires and one of them needs a host of its own (its ingress is therefore off by default). `clusterIssuer`, `className` and `annotations` stay global defaults under `ingress.` and are overridable per app.
 
 ### 5. Security hardening