Refactor App into TS modules; add tsc typecheck

src/lib/reading.ts

@@ -0,0 +1,31 @@
+// Spritz ORP algorithm - position where the eye naturally fixates.
+// Based on Optimal Viewing Position research (20-35% from left).
+export function getORPIndex(wordLength: number): number {
+  if (wordLength <= 0) return 0;
+  if (wordLength === 1) return 0; // 1 char: 1st letter
+  if (wordLength <= 5) return 1; // 2-5 chars: 2nd letter
+  if (wordLength <= 9) return 2; // 6-9 chars: 3rd letter
+  if (wordLength <= 13) return 3; // 10-13 chars: 4th letter
+  return 4; // 14+ chars: 5th letter
+}
+
+export function getWordDelay(word: string, baseDelayMs: number): number {
+  let multiplier = 1;
+  multiplier += Math.sqrt(word.length) * 0.04;
+  if (/[.!?]$/.test(word)) {
+    multiplier = 2.5;
+  } else if (/[,;:]$/.test(word)) {
+    multiplier = 1.8;
+  }
+  return baseDelayMs * multiplier;
+}
+
+export function formatReadingTime(minutes: number): string {
+  if (minutes < 1) return "< 1 min";
+  if (minutes < 60) return `${Math.round(minutes)} min`;
+  const hours = Math.floor(minutes / 60);
+  const mins = Math.round(minutes % 60);
+  if (mins === 0) return `${hours}h`;
+  return `${hours}h ${mins}m`;
+}
+