feat(labs): add Lab-OCR scan and review screen

Add the Scan a report entry to the Labs page, gated on the capability probe.
The review dialog uploads a photo or PDF, then shows each proposed reading for
per-row confirm, edit, or discard with duplicate, new-biomarker, and
low-confidence hints in the labs design language. Only confirmed rows commit.
Add the OCR query key and the six-locale strings.

src/lib/query-keys/labs.ts

@@ -33,4 +33,8 @@ export const labKeys = {
   // the manager; both invalidate `biomarkers()` after a mutation.
   biomarkers: () => ["biomarkers"] as const,
   biomarkerDetail: (id: string) => ["biomarkers", "detail", id] as const,
+
+  // v1.18.9 — Lab-OCR capability probe (drives whether the "Scan a report"
+  // affordance shows). Cheap GET; the dialog refetches it on open.
+  ocrCapability: () => ["lab-ocr", "capability"] as const,
 };