Six things that looked like they worked

None of these fails loudly and two of them correct themselves if you reload,
which is why five were found by reading rather than by anybody reporting them.

The reply that lost its author is the one worth knowing about: the frame that
replaces a bubble when a reply lands was looking the models up as nobody, and
"no user" answers "no models" rather than "all models" -- so every finished
reply swapped the model's avatar for the plain mark and put the instance's name
where the model's should be, until the next page load put it back.

Beside it: a concurrency quota enforced on two of the six paths that start a
reply, including neither of the two most used; a custom theme whose success and
warning colours moved the text and left the background behind; a phone shell
sized to one viewport inside a document sized to another, which is the reported
scroll past the bottom of Settings; a whole conversation's Markdown rendered on
every page load and read by nothing; a skip guard inert since it was written;
and an endpoint nothing has ever called.

The scroll fix folded five near-identical scroller rules into one, which is
also where the containment they were all missing now lives.

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

src/lembas/services/branding.py

@@ -462,7 +462,20 @@ def theme_css(theme: Theme) -> str:
     if not theme.tokens:
         return ""
     lines = [f"  --{name}: {value};" for name, value in theme.tokens.items()]
-    for name, alpha in (("accent", "0.14"), ("leaf", "0.14"), ("danger", "0.14")):
+    # Every settable colour that has a `-soft` companion in tokens.css, not the
+    # three somebody stopped at. `success` and `warning` were settable and their
+    # softs were not derived, so a custom theme moved the text and left the
+    # background behind it in the base theme's hue -- an alert, a badge, a
+    # permission's "on" state and the `+` lines of every agent diff, each in two
+    # colours that were never meant to meet. Precisely the half-working failure
+    # this function's own docstring says it exists to prevent.
+    for name, alpha in (
+        ("accent", "0.14"),
+        ("leaf", "0.14"),
+        ("danger", "0.14"),
+        ("success", "0.14"),
+        ("warning", "0.14"),
+    ):
         soft = _soft(theme.tokens.get(name, ""), alpha)
         if soft:
             lines.append(f"  --{name}-soft: {soft};")