SX Reactive Islands

Signals transpiled from signals.sx spec via bootstrap_js.py

1. Signal: Counter

0

signal + computed + effect

2. Batch: Two signals, one notification

first: 0 second: 0

batch coalesces writes: 2 updates, 1 re-render

3. Effect: Auto-tracking + Cleanup

effect returns cleanup fn; dispose stops tracking

4. Computed chain: base → doubled → quadrupled

base: 1
doubled:   quadrupled:

Three-level computed dependency graph, auto-propagation