Task 436: Sync Calculator.js Presets from Templates.ts

Status: DONE

Summary

calculator.js (browser runtime) has its own hardcoded copy of EPISODE_PRESETS with ship parameters (48000t, 9.8 MN, 6.37 MN). These duplicate what templates.ts now derives from KESTREL constants. Make templates.ts inject the preset data as inline JSON that calculator.js reads, eliminating the duplication.

Approach

1. In templates.ts, serialize the presets into a <script type="application/json" id="calc-presets-data"> tag
2. In calculator.js, read presets from the data tag instead of hardcoding them
3. Add a test to verify the data injection works