Grabbed dndbeyond's source code

```
~/go/bin/sourcemapper -output ddb -jsurl https://media.dndbeyond.com/character-app/static/js/main.90aa78c5.js
```

ddb_main/subApps/sheet/constants.ts

@@ -0,0 +1,23 @@
+export const sidebarId = "sidebar";
+
+export const SIGNED_32BIT_INT_MAX_VALUE = 1_000_000_000;
+export const SIGNED_32BIT_INT_MIN_VALUE = -1_000_000_000;
+
+export const HP_TEMP_VALUE = {
+  MAX: 999,
+  MIN: 0,
+};
+
+export const HP_BONUS_VALUE = {
+  MAX: 99,
+  MIN: -99,
+};
+
+export const HP_OVERRIDE_MAX_VALUE = 999;
+
+export const HP_BASE_MAX_VALUE = 500;
+
+export const HP_DAMAGE_TAKEN_VALUE = {
+  MAX: SIGNED_32BIT_INT_MAX_VALUE,
+  MIN: 0,
+};