feat: ctrl+s searches everything; again narrows to the source you're in

Go to opens on All instead of the source you're in, so a search finds
anything at once. ctrl+s again in Go to narrows to that source, and once
more goes back to All; the hint names it. g/G go to the top and bottom
of a list while browsing, and the tabs are Search, Favourites, Recent.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/keys.md

@@ -87,17 +87,20 @@ selected item.
 Search has the scope on the left (All; all of Azure, Databricks or repos;
 or one source; with `○ ◐ ●` for how much of it is loaded) and what's in
 it on the right. All repos searches every repo without asking Azure or
-Databricks for anything. It opens on the
-source you're in. Typing a search loads what it covers: everything on
-All, else the source picked; results appear as lists arrive. That's once
-each time Go to opens, and only what isn't loaded yet; `ctrl+a` loads
-again, lists that failed included.
+Databricks for anything. It opens on All; `ctrl+s` again narrows it to
+the source you're in, and once more goes back to All. Typing a search
+loads what it covers: everything on All, else the source picked;
+results appear as lists arrive. That's once each time Go to opens, and
+only what isn't loaded yet; `ctrl+a` loads again, lists that failed
+included.
 
 Like a pane, Go to is either browsing or typing a filter:
 
 | Browsing | Typing | Action |
 |---|---|---|
 | `j`/`k` | `ctrl+j`/`ctrl+k` | move |
+| `g`/`G` | | top / bottom |
+| `ctrl+s` | `ctrl+s` | only the source you're in / All |
 | `h`/`l`, `tab` | `ctrl+h`/`ctrl+l`, `tab` | scope list / results |
 | `[` / `]` | | previous / next tab |
 | `f` | `ctrl+f` | star |