Mobile UI pass: sheet swipe, ice-scene layering, contrast, touch targets

Phones (<=639px) only for layout/gestures; the theme-level fixes apply
everywhere, as they are token/design changes.

Settings sheet
- Swipe-to-dismiss reusing the InstallSheet gesture: the sheet follows the
  finger, closes past ~90px or on a fast flick, snaps back otherwise. Drag
  starts only from the handle/header and only while the body is scrolled to
  the top. Backdrop tap still closes.
- Fixed header + scrollable body: pb-safe + spacer, so nothing is clipped;
  a scroll cue (chevron) fades in while more content is below and out at
  the end.
- Show/Save stack under the field at 44px on phones; close, Test connection
  and Remove key are 44px too. Remove key is now a rose destructive action
  with a confirmation that the full-screen key setup comes back.
- API key note split into a short privacy line plus a collapsible
  'Using the local daemon?' tip (OLLAMA_AUTH=local / .env.local / signin).
- Fixed the missing space in the English tip ('ollama signin instead.').
- Health: kept the auto-check and banner; added a loading row and a
  'Checked just now' / 'Checked at HH:MM' freshness label (also for errors).

Ice scene / readability
- Verified the orbs were never above content (fixed z-index:-1 layer,
  pointer-events:none); they were just shining through the glass. Phones get
  lower blob/orb opacity and orbs tucked to the edges; the bottom-right orb
  is moved out from under the tab bar and the tab bar paints a more opaque
  surface so its labels hold contrast.

Contrast / themes
- Dark --text-subtle raised to #9db1d0 (8.6:1 page, 7.2:1 glass); helper
  text now uses the tokens.
- Disabled buttons are a visible muted chip (.btn-disabled) instead of a
  40%-opacity ghost.
- One ice primary gradient in both themes; danger/success now actually show
  their colour (bg-none strips the primary background-image that used to
  paint over !bg-rose-600).
- Light mode: cool card rims instead of white-on-white, stronger shadow.

Redundancy / touch
- Removed only the header gear; the hamburger drawer (folders, Settings,
  theme) and the tab-bar Settings stay.
- Theme toggle is a bordered chip with an action aria-label (drawer row too).
- Empty library hides the folder pills, demotes Import to a quiet link and
  keeps a single primary CTA. 44px targets for nav rows, segmented control
  and folder pills on phones.
- Fixed a pre-existing 16px horizontal overflow (header -mx-4 vs a
  padding-less parent) and let info values wrap instead of truncating.

Verified: mobile suite 47/47 (EN+CS, 360/390px), pixel-sampled contrast
audit 0 runs below WCAG AA (8 runs, both themes/locales; axe marks the glass
'incomplete'), i18n 27/27, desktop regression 72/72, lint + build clean.
Service worker cache bumped to freezmo-v5.

components/LibraryScreen.tsx

@@ -119,23 +119,38 @@ export function LibraryScreen() {
           </div>
 
           <div className="flex flex-wrap items-center gap-2">
-            <Button
-              variant="secondary"
-              size="md"
-              className="lg:hidden"
-              onClick={() => importRef.current?.click()}
-            >
-              <UploadIcon className="size-4" />
-              {t("library.import")}
-            </Button>
-            <button
-              type="button"
-              onClick={() => importRef.current?.click()}
-              className="hidden items-center gap-1.5 text-[13px] font-medium text-[var(--text-muted)] transition hover:text-[var(--text)] hover:underline lg:inline-flex"
-            >
-              <UploadIcon className="size-4" />
-              {t("library.import")}
-            </button>
+            {/* With nothing in the library, Import drops to a quiet text link
+                so the single primary action is “Make your first deck”. */}
+            {isEmpty ? (
+              <button
+                type="button"
+                onClick={() => importRef.current?.click()}
+                className="inline-flex items-center gap-1.5 text-[13px] font-medium text-[var(--text-muted)] transition hover:text-[var(--text)] hover:underline"
+              >
+                <UploadIcon className="size-4" />
+                {t("library.import")}
+              </button>
+            ) : (
+              <>
+                <Button
+                  variant="secondary"
+                  size="md"
+                  className="touch-target lg:hidden"
+                  onClick={() => importRef.current?.click()}
+                >
+                  <UploadIcon className="size-4" />
+                  {t("library.import")}
+                </Button>
+                <button
+                  type="button"
+                  onClick={() => importRef.current?.click()}
+                  className="hidden items-center gap-1.5 text-[13px] font-medium text-[var(--text-muted)] transition hover:text-[var(--text)] hover:underline lg:inline-flex"
+                >
+                  <UploadIcon className="size-4" />
+                  {t("library.import")}
+                </button>
+              </>
+            )}
             <input
               ref={importRef}
               type="file"
@@ -167,23 +182,28 @@ export function LibraryScreen() {
           </p>
         ) : null}
 
-        {/* Mobile folder switcher; the sidebar covers desktop. */}
-        <FolderBar className="lg:hidden"
-          folders={folderList}
-          counts={counts}
-          selected={selected}
-          onSelect={(id) => {
-            setSelected(id);
-            setConfirmDelete(null);
-          }}
-          onCreated={(id) => {
-            setSelected(id);
-            setMessage({
-              tone: "ok",
-              text: t("library.folderCreated"),
-            });
-          }}
-        />
+        {/* Mobile folder switcher; the sidebar covers desktop. With an empty
+            library there is nothing to filter, and the pills would compete
+            with the empty state's single call to action. */}
+        {!isEmpty ? (
+          <FolderBar
+            className="lg:hidden"
+            folders={folderList}
+            counts={counts}
+            selected={selected}
+            onSelect={(id) => {
+              setSelected(id);
+              setConfirmDelete(null);
+            }}
+            onCreated={(id) => {
+              setSelected(id);
+              setMessage({
+                tone: "ok",
+                text: t("library.folderCreated"),
+              });
+            }}
+          />
+        ) : null}
 
 
         {message ? (
@@ -204,7 +224,7 @@ export function LibraryScreen() {
         <EmptyState
           title={t("library.noDecks")}
           action={
-            <Link href="/create" className="btn-primary h-10 px-4 text-sm">
+            <Link href="/create" className="btn-primary touch-target h-10 px-4 text-sm">
               {t("library.makeFirst")}
             </Link>
           }