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 # AGENTS.md — Project state, review findings, open items, and working rules
 
 **Last updated: 2026-08-30** (owner findings batch - vehicle pin, tile chevrons, select arrows,
-SmartDeal dialog, address cache and pull-to-refresh; manifest `2026.8.30.16`, see sections AO and AP.
+SmartDeal dialog, address cache and pull-to-refresh; manifest `2026.8.30.19`, see sections AO, AP and AQ.
 Before that: design-audit follow-through - the five priority items applied to
 both codebases, plus the location preview's wrong pin; manifest `2026.8.30.8`, see section AN.
 Before that: third parity round — the panel had never actually rendered Audi
@@ -6007,6 +6007,49 @@ the flag disappear. A check that has never been seen to fail is not evidence of
 
 ---
 
+
+## AQ. `node --check` cannot verify the panel bundle - check it as a module (2026.8.30.19)
+
+**The failure.** `audi-dashboard-app.js` was syntactically broken from `2026.8.30.14` to `.18` - five
+versions, all pushed to Gitea. The panel could not be parsed, `connectedCallback()` aborted, the
+custom element ended up with **no shadow root at all**, and every page rendered blank. The owner hit
+it on the real instance after updating to `.17` and restarting.
+
+**The cause** was a one-line editing mistake: the rationale comment for the "Zündung an" change went
+*inside* a `${...}` expression instead of into the surrounding markup text. Inside `${ }` the content
+is JavaScript, so `<!--` is not an HTML comment there.
+
+**Why the standing check missed it, which is the part worth keeping.** `node --check datei.js` parses
+as a **script**, and in scripts HTML-like comments (`<!--`, `-->`) are explicitly legal under Annex B
+of the language standard. The browser loads the very same file as a **module**, where they are
+forbidden. So the project's habitual verification step is structurally incapable of catching this
+class of error - it is not that it was run carelessly, it cannot find it.
+
+**Rule from now on:** verify the panel bundle with the module grammar before shipping.
+
+```bash
+cp custom_components/audi_dashboard/frontend/audi-dashboard-app.js /tmp/probe.mjs && node --check /tmp/probe.mjs
+```
+
+The `.mjs` extension is the whole point - it switches Node to the same grammar the browser uses. Run
+it over every file in `frontend/`, not just the big one. Applied retroactively across the day's
+commits, this pinpointed `.14` as the first broken version in seconds.
+
+**A second failure made it last five versions.** After `.14` the panel tab was never reloaded. Every
+later "verified live" statement about the panel ran against the still-resident old script and was
+therefore worthless - the page kept working precisely *because* it was stale. **Reload the panel
+after every deploy before claiming anything about it**, and confirm the version actually served:
+
+```js
+performance.getEntriesByType('resource').filter(e => /audi-dashboard-app/.test(e.name)).map(e => e.name)
+```
+
+A blank panel has a reliable signature worth recognising: the element exists but `element.shadowRoot`
+is `null`. That means `connectedCallback()` threw - look for a parse error in the bundle, not for a
+rendering bug in a view.
+
+---
+
 ## Working conventions (observed — keep them)
 
 - German is the project language: identifiers, comments, commits, UI texts. Exceptions: