Fix Backup type helper text showing both explanations at once (v0.16.17)

ROADMAP.md

@@ -158,3 +158,5 @@ Roughly in priority order:
 `v0.16.15` cleans up the Groups tab's layout: removed the redundant "Groups / Organize users for Access List permissions." heading, since the tab button and admin panel description already say what the tab is, and it was adding a bare, boxless line of text found nowhere else in Administration once the tab's own Create button moved to the shared header. The Enabled/Disabled stat bar is now the first thing in the panel, structurally matching how the Users tab's own stat bar is positioned. Also added top spacing between the Administration page's subtitle and the row of tab buttons (System, Users, Groups, ...) below it -- that gap had never been set, so the tabs bar sat flush against the subtitle text.
 
 `v0.16.16` ships a batch of fixes found in live use: the Backup type picker (in both the scheduled-backup form and the manual "Create a backup" dialog) no longer shows a long wrapped sentence as the selected value -- it now shows a short "Complete (Recommended)" / "Configuration only" label with the detail moved into the helper text beneath it, and the in-app documentation now explicitly names the "Backup type" field so it's easy to find by search. The Performance page's "Outliers / Slowest requests" section has been removed, along with the per-row error-count badge in the "Throughput by domain" table -- both added noise without being worth the space for most setups. That table's column headers now stay pinned while scrolling instead of scrolling out of view. Rows for domains with no matching Hosted Site, Proxy Host, or Redirect Host are now badged "Not configured" -- that table is built from Caddy's raw access log, so it always included every hostname a request was ever seen for (including scanner/bot traffic hitting made-up subdomains that fall through to the Default Site handler), not just domains you've actually configured; the badge makes that distinction visible instead of leaving it to guesswork. Finally, the Administration Users tab no longer flashes "No users found." for a moment before the user list has actually loaded.
+
+`v0.16.17` fixes the Backup type helper text showing both the Complete and Configuration-only explanations stacked on top of each other on page load or refresh, instead of just the one matching the currently selected option. Root cause: the help text only ever updated on the select's `change` event -- but `renderBackups()` sets the select's value from saved settings on every render without firing a `change` event, so the static placeholder text (which briefly held both sentences as a v0.16.16 authoring mistake) never got replaced until you manually touched the dropdown. Factored the text-selection logic into its own function and call it both on `change` and every time `renderBackups()` runs, so it always matches the select's actual current value.