Function getDonorLevel

getDonorLevel(amount: string | number): DonorLevel
Bucket a donation amount into a DonorLevel. Truncates (Math.trunc) before comparison so 24.99 → grey, matching the historical Number.parseFloat → truncation flow. Accepts strings (Tiltify's amount.value is always a decimal string on the wire) or numbers.
Parameters
- amount: string | number
Returns DonorLevel
Example
```
getDonorLevel("100")   // "platinum"
  getDonorLevel(74.99)   // "silver" (24.99 above bronze, below gold)
  getDonorLevel("n/a")   // "grey"  (unparseable → floor bucket)
```
- Defined in fundraiser-data/src/projections/index.ts:427