feat(rsc): Detect single RSA functions (not just entire files)

[Tobbe]

Our "analyze" vite plugin now also finds inlined RSAs.

export const ServerDelayForm = () => {
  let delay = 0;

  if (fs.existsSync("settings.json")) {
    delay = JSON.parse(fs.readFileSync("settings.json", "utf8")).delay || 0
  }
 
  return (
    <div className="server-delay-form">
      <form
        action={async (formData) => {
          // The "use server" here is what's interesting and important
          "use server"

          await fs.promises.writeFile(
            "settings.json",
            `{ "delay": ${formData.get("delay") } }\n`
          )
        }}
      >
        <label htmlFor="delay">
          <div>Delay ({delay}ms)</div>
          <input type="number" id="delay" name="delay" />
        </label>
        <button type="submit">Set</button>
      </form>
    </div>
  )
}