The source-picker refactor introduced a new stable DOM structure inside
`#gsearch-results`:
<div id="gsearch-results"> <!-- max-height: 60vh, flex-col -->
<div id="gsearch-source-row" /> <!-- icon row, controller-rendered -->
<div id="gsearch-fallback-banner" />
<div id="gsearch-body" /> <!-- surface renders results here -->
</div>
But the companion CSS never landed. `#gsearch-body` had default block
layout, so when results exceeded the 60vh cap, they clipped silently
instead of scrolling. The old structure had `.gsearch-results-body`
with `overflow-y: auto; flex: 1` directly inside the panel; that rule
still exists but its selector now matches a nested div with no flex
parent, so `flex: 1` is a no-op and overflow doesn't trigger.
Fix: give the three stable children the right flex behaviour so the
body fills remaining space and scrolls.
- `#gsearch-source-row` and `#gsearch-fallback-banner` stay at natural
height (flex-shrink: 0).
- `#gsearch-body` grows (flex: 1 1 auto), can shrink below content
height (min-height: 0 — this is the critical bit, otherwise flex
items won't shrink below their intrinsic size and overflow never
triggers), and scrolls vertically.
Styled scrollbar matches the rest of the panel (4px, translucent thumb).
2b7d6c8c7c