refactor(labs): align Labs settings with the standard Settings pattern

Restructure the Labs settings sub-page to the canonical Settings dialect:
each block is a SettingsCard with a SettingsCardHeader (neutral icon, title,
short description), matching the AI / notifications / mood sections instead of
bare sections with text-sm headings. Surface the new alphabetical sort options
in the sort select.

messages/en.json

@@ -6492,6 +6492,8 @@
       "label": "Order of values",
       "recentDesc": "Most recent reading first",
       "recentAsc": "Oldest reading first",
+      "alphaAsc": "Name (A–Z)",
+      "alphaDesc": "Name (Z–A)",
       "manual": "Sort manually",
       "hint": "With manual sorting you can drag the biomarkers below into your own order."
     },