fix(ui): defensive optional chains on all remaining var?.x.y sites

Marc reported many residual TypeError crashes after the targeted fix
in 680b001. A comprehensive perl regex sweep across src/app and
src/components turned up 19 more occurrences of the same anti-
pattern: `var?.x.y` only protects the outer object, so when the
inner field is undefined the access throws.

Touched files:
  - src/app/api/dashboard/summary/route.ts (server-side null guards)
  - src/app/api/health/route.ts (session check)
  - src/components/admin/feedback-inbox-section.tsx
  - src/components/medications/medication-card.tsx (compliance rates)
  - src/components/medications/medication-form.tsx
  - src/components/medications/intake-history-list.tsx
  - src/components/measurements/measurement-list.tsx
  - src/components/mood/mood-list.tsx
  - src/components/ui/password-strength.tsx

Pattern applied: `var?.outer.inner` → `var?.outer?.inner`. Tests
green, typecheck clean. Lint untouched (the rule we already enforce
catches set-state-in-effect, not optional-chain depth).

src/components/admin/feedback-inbox-section.tsx

@@ -49,7 +49,7 @@ export function FeedbackInboxSection({ id }: { id: string }) {
   const { t } = useTranslations();
   const queryClient = useQueryClient();
   const { data: status } = useSystemStatus();
-  const githubConfigured = Boolean(status?.integrations.bugReport?.configured);
+  const githubConfigured = Boolean(status?.integrations?.bugReport?.configured);
 
   const [activeStatus, setActiveStatus] = useState<FeedbackStatusType>("OPEN");
   const [selected, setSelected] = useState<FeedbackItem | null>(null);
@@ -65,7 +65,7 @@ export function FeedbackInboxSection({ id }: { id: string }) {
     },
   });
 
-  const counts = data?.meta.countsByStatus ?? {};
+  const counts = data?.meta?.countsByStatus ?? {};
 
   function refresh() {
     queryClient.invalidateQueries({ queryKey: ["admin", "feedback"] });
@@ -113,7 +113,7 @@ export function FeedbackInboxSection({ id }: { id: string }) {
                   {t("admin.feedback.loading")}
                 </span>
               </div>
-            ) : !data?.items.length ? (
+            ) : !data?.items?.length ? (
               <p className="text-muted-foreground text-sm">
                 {t("admin.feedback.noEntries")}
               </p>