Add blog post: TypeScript's satisfies operator

[Copilot]

Adds a new published post explaining TypeScript 4.9's satisfies operator — the type-checking primitive that validates a value against a type without widening the inferred type.

New post: 2026-04-28-typescript-satisfies-operator.md

• Demonstrates the core problem: type annotations widen inferred types, losing tuple/literal precision
• Shows satisfies as the solution: constraint check + preserved narrow type
• Real-world example: route config map where literal method types ("GET") remain accessible downstream
• Comparison of satisfies vs type annotation vs as in a summary table

const palette = {
  red: [255, 0, 0],
  green: "#00ff00",
} satisfies Record<string, Color>;

palette.red.map((v) => v * 2); // ✅ still typed as [number, number, number]
palette.red.toUpperCase();     // ❌ compile error — not widened to Color