Fix incorrect condition in "Chains of computations" example

[PaulyBearCoding]

Fixes #8097

Problem

In the "Chains of computations" section, the refactored example uses an incorrect condition that changes the game logic from the original:

// Current (incorrect)
if (goldCardCount <= 3) {
  setGoldCardCount(goldCardCount + 1);
} else {
  // advance round
}

This allows 5 gold cards before advancing the round, which differs from the original Effect-based example that advances after 4 gold cards.

Solution

Changed the condition from <= to <:

// Fixed
if (goldCardCount < 3) {
  setGoldCardCount(goldCardCount + 1);
} else {
  // advance round
}

Why This Fix is Correct

The original "bad" example increments first, then checks:

useEffect(() => {
  setGoldCardCount(c => c + 1);  // 0→1, 1→2, 2→3, 3→4
}, [card]);

useEffect(() => {
  if (goldCardCount > 3) {  // Triggers when count reaches 4
    setRound(r => r + 1);
    setGoldCardCount(0);
  }
}, [goldCardCount]);

This advances after 4 cards (when count reaches 4).

The fixed example checks before incrementing:

• With <= 3: Allows counts 0,1,2,3 to increment → 4 values → advances on 5th card ❌
• With < 3: Allows counts 0,1,2 to increment → 3 values → advances on 4th card ✅

Testing

Verified the fix by:

1. Tracing execution logic step-by-step
2. Building the docs site locally and confirming correct rendering
3. Checking that only the intended line was modified

Changes

• File: src/content/learn/you-might-not-need-an-effect.md
• Line: 440
• Change: goldCardCount <= 3 → goldCardCount < 3

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