diff --git a/2026/2026-08-17--bonfire-chromium-login.md b/2026/2026-08-17--bonfire-chromium-login.md
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+# Bonfire — Chromium login stays on homepage (2026-08-17)
+
+Site: **https://bonfire.hacktivism.ch/**  
+Canonical: `configs/bonfire/README.md` (section *Login in Chromium*).
+
+## Symptom
+
+- **Firefox:** Log in and `/login` work.
+- **curl** `https://bonfire.hacktivism.ch/login`: 200, title *Log in*.
+- **Chromium** (operator profile, tab on `/`): **Log in** click does nothing; typing `/login` in the address bar still shows *Explore local activities*. Incognito/Firefox not affected.
+
+Not the `isoc` account (email + username profile exist; login API ok).
+
+## Checks
+
+| Check | Result |
+|-------|--------|
+| Guest `/` HTML | `data-live-socket="false"`; **Log in** is `<a href="/login" data-phx-link="redirect">` |
+| `#modal` | `opacity-0 modal-closed`; `modal_invisible` loading stub has **no CSS rule** (Chromium can show a black overlay) |
+| Bonfire JS | `navigator.serviceWorker.register("/pwabuilder-sw.js", {scope: "/"})` |
+| `/pwabuilder-sw.js` (before kill-switch) | 404; hashed `pwabuilder-sw-*.js` exists under `priv/static/` |
+| UI | badge **Federation disabled** while container `FEDERATE=true` |
+
+## Workaround
+
+Unregister the worker for `bonfire.hacktivism.ch` in that Chromium profile (`chrome://serviceworker-internals` or DevTools Application), clear site data, hard reload. Then `/login` matches Firefox.
+
+Host copies (optional, recreate-volatile in the image): `~/koopa-bonfire/data/branding/{pwabuilder-sw.js,hacktivism-login-fix.css,unregister-sw.js}`.
diff --git a/configs/bonfire/README.md b/configs/bonfire/README.md
index 8ce50a4..fa886a0 100644
--- a/configs/bonfire/README.md
+++ b/configs/bonfire/README.md
@@ -25,4 +25,26 @@ scripts/bonfire/install-systemd.sh
 Units: `container-koopa-bonfire-db`, `container-koopa-bonfire`, `gitbot-mirror`.  
 Needs `loginctl enable-linger hernani`. Run `podman-compose up -d` once before first boot.
 
-Public feeds: `public-feeds.md`.
\ No newline at end of file
+Public feeds: `public-feeds.md`.
+
+## Login in Chromium (PWA service worker)
+
+Firefox and `curl` reach https://bonfire.hacktivism.ch/login (200, real form).  
+**Chromium** (same URL or the yellow **Log in** buttons) can stay on the guest homepage. Not an account/password bug.
+
+Cause (two layers):
+
+1. **Service worker** — Bonfire JS registers `/pwabuilder-sw.js` with `scope: "/"`. An old worker in the Chromium profile intercepts navigations (including `/login`) and serves the cached start page. Firefox typically has no worker → login works there.
+2. **Guest homepage** — static cache / `data-live-socket="false"` plus LiveView `data-phx-link="redirect"` on **Log in**. Without a live socket the click is swallowed. Guest HTML can also leave an empty `modal_invisible` overlay (black panel in Chromium).
+
+Workaround (this Chromium profile):
+
+- `chrome://serviceworker-internals` → **bonfire.hacktivism.ch** → Unregister  
+  or DevTools → Application → Service Workers → Unregister + Clear site data  
+- hard reload, then open `/login`  
+- or **Incognito** (no SW)
+
+Server-side notes (host `~/koopa-bonfire/data/branding/`, not a substitute for unregister): kill-switch `pwabuilder-sw.js`, overlay CSS, login-click JS. Container copies are overwritten on image recreate.
+
+Daylog: `2026/2026-08-17--bonfire-chromium-login.md`.  
+UI badge **Federation disabled** can still show while `.env` has `FEDERATE=true` (see `2026/2026-07-10--bonfire-federate.md`).
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