docs(skill): pin the upstream digest for revert comparisons, and note layer whiteouts

Both raised in review of #3028: with build_from :latest a revert only
discriminates when both builds resolve the same upstream image, and plain tar
does not process OCI whiteouts when reconstructing a rootfs from layers.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.claude/skills/hassio-addon-workflow/references/evidence.md

@@ -58,3 +58,60 @@ Once the rebuilt add-on is running, re-run the measurement that motivated the wo
 cannot be self-verified — a service that reads its environment only at start makes an env-var fix
 unproven until the add-on restarts, which needs the user or `ha-cli` with their agreement. If you
 cannot restart, the change is **Assumed**, not Verified, and must be reported that way.
+
+## A local reproduction that passes does not outrank a user's production report
+
+PR #3026 added an nginx `sub_filter` to the `filebrowser_quantum` ingress vhost. After it merged,
+the user reported that Download had stopped working — the file opened inline instead. Every check
+run against the change came back clean:
+
+- the shipped bundle's Download action builds an `<a href>` and clicks it, and never calls
+  `window.open`, which is all the injected shim overrides;
+- the shim's own predicate, evaluated live in the running app, returned false for the download
+  URL, the `inline=true` raw URL and the public-share download URL;
+- the download response through the vhost was **byte-identical** with and without the `sub_filter`
+  (`Content-Disposition: attachment` intact, `Content-Length` unchanged), for `text/plain` and for
+  the `text/html` case the filter actually scans;
+- upstream's frontend download code is unchanged from v1.5.0-stable to v1.5.4-stable, and Home
+  Assistant's ingress iframe carries no `sandbox` attribute (`ha-panel-app.ts`), so downloads are
+  not sandbox-blocked either.
+
+None of that reproduced the failure, and none of it explained the one fact that mattered: the user
+saw it fail under ingress and work on the add-on's direct port, and the `sub_filter` was the only
+ingress-side change in that update. **Revert first and keep investigating.**
+
+A revert can also discriminate — if the symptom survives it, the cause was the concurrent upstream
+bump rather than the diff — but only if **both builds resolve the same upstream image**. With
+`build_from: <image>:latest` they need not: `latest` can move between the two rebuilds, and then
+the comparison proves nothing. Resolve the tag to a digest and record it before and after, or pin
+`build_from` to that digest for the duration of the experiment:
+
+```bash
+T=$(curl -s "https://auth.docker.io/token?service=registry.docker.io&scope=repository:<repo>:pull" | jq -r .token)
+curl -s -H "Authorization: Bearer $T" \
+     -H "Accept: application/vnd.oci.image.index.v1+json" \
+     "https://registry-1.docker.io/v2/<repo>/manifests/latest" \
+  | jq -r '.manifests[] | select(.platform.architecture=="amd64" and .platform.os=="linux") | .digest'
+```
+
+For the case above both builds resolved `gtstef/filebrowser:latest` amd64 to
+`sha256:e549e1a9b5de573c276f7be67444841559e3f89cbc664a2f926968453d069436` (v1.5.4-stable, created
+2026-08-29T14:19:56Z), so that comparison was controlled — but it was luck, not design.
+
+Worth building next time, because it took most of the session and is reusable: a reproduction rig
+made **out of the published image's own layers**, with no dockerd. Pull the manifest and blobs from
+the registry with `curl` + `jq`, untar them in order, then run the extracted binary through the
+image's own musl loader (`root/lib/ld-musl-x86_64.so.1 ./filebrowser`) with the real `http/dist`
+next to it. Plain `tar` does not interpret whiteouts, so a file a later layer deletes
+(`.wh.<name>`) or a directory it marks opaque (`.wh..wh..opq`) survives into the reconstructed
+rootfs; check with `tar tzf <layer> | grep '\.wh\.'` and reach for an OCI-aware unpacker if any
+turn up. (There were none in `gtstef/filebrowser:latest` — all eleven layers, 0 whiteout entries —
+so that rig was faithful.) Put the add-on's rendered `ingress.conf` in front of it, and a second nginx server in
+front of that to strip the `/api/hassio_ingress/<token>` prefix the way Supervisor does. That gets
+the real frontend, the real backend and the real vhost under a browser — everything except
+Supervisor itself.
+
+**`build_from: <image>:latest` means every merge ships an upstream version bump too.** Record which
+upstream version each add-on image was built from — the registry config blob's `created` timestamp,
+the resolved manifest digest, and the binary's version string — before attributing a regression to
+the diff.

filebrowser_quantum/CHANGELOG.md

@@ -1,4 +1,9 @@
  
+## 1.5.3.2 (2026-08-30)
+- Revert the 1.5.3.1 ingress filter while a report of broken downloads is
+  investigated. "Open parent directory" in the tool views opens a new tab
+  again, as it did up to 1.5.3.
+ 
 ## 1.5.3.1 (2026-08-29)
 - Fix "open parent directory" in Tools -> File Size Analyzer under Home
   Assistant ingress. FileBrowser opened the parent folder in a new tab, which

filebrowser_quantum/config.yaml

@@ -118,4 +118,4 @@ schema:
 slug: filebrowser_quantum
 udev: true
 url: https://github.com/alexbelgium/hassio-addons
-version: "1.5.3.1"
+version: "1.5.3.2"

filebrowser_quantum/rootfs/etc/nginx/servers/ingress.conf

@@ -3,7 +3,7 @@ server {
 
     include /etc/nginx/includes/server_params.conf;
     include /etc/nginx/includes/proxy_params.conf;
-
+    
     client_max_body_size 0;
 
    location / {
@@ -12,35 +12,6 @@ server {
        proxy_send_timeout 30m;
        proxy_read_timeout 30m;
        proxy_pass         %%protocol%%://backend%%subpath%%;
-
-       # Tools -> File Size Analyzer (and the other tool views) open a result's
-       # parent folder with window.open(<absolute url>, '_blank'), because
-       # goToItem() takes its newTab argument from the context menu's
-       # showLimitedOptions flag, which those views always set. Behind ingress
-       # that popup lands on the raw /api/hassio_ingress/<token>/ url with no
-       # Home Assistant frontend around it to keep the ingress session alive,
-       # so the new tab answers 401 instead of showing the folder. Turn that
-       # popup into a navigation of the panel itself.
-       #
-       # The context menu's "go to item" action, which search results and the
-       # tool views also offer, hardcodes the same new tab and is fixed too.
-       #
-       # Scoped to the two prefixes goToItem() builds, "files/" and
-       # "public/share/", so the window.open calls that download or preview a
-       # file (they go to api/resources/download) keep their own tab: sending
-       # an inline raw file to location.assign would replace the whole app.
-       # A link out of the add-on keeps its own tab as well, unless a user
-       # points a sidebar link (or a link inside a file open in the editor) at
-       # this same instance's files/ or public/share/ route, which then also
-       # opens in the panel. Same shape as the komga add-on's ingress filter.
-       #
-       # Injected into the page's existing nonce-carrying inline script rather
-       # than next to <div id="app">: FileBrowser sends
-       # script-src 'self' 'nonce-<random>', so a standalone inline <script>
-       # would be blocked. If upstream ever drops that
-       # window.__pwaDeferredPrompt line the filter simply stops matching and
-       # the popup behaviour returns, which is the pre-fix state.
-       sub_filter "window.__pwaDeferredPrompt = null;" "window.__pwaDeferredPrompt = null;(function(){var o=window.open;window.open=function(u,n,f){try{var b=(window.globalVars||{}).baseURL;if(u&&n==='_blank'&&!f&&b){if(b.slice(-1)!=='/')b+='/';var t=new URL(u,location.href);if((t.protocol==='http:'||t.protocol==='https:')&&t.origin===location.origin&&(t.pathname.indexOf(b+'files/')===0||t.pathname.indexOf(b+'public/share/')===0)){location.assign(t.href);return window}}}catch(e){}return o.apply(window,arguments)}})();";
   }
 
 }