You are building a Telegram bot in TypeScript using `grammy` or `telegraf`. The bot has access to a user's connected EVM wallet via a custodied key tied to chat id (assume the wallet infra is solved; just call `signMessage` and `signTransaction`).
Implement `/buy <symbol_or_address> <amount_in_usd>` and `/sell <symbol_or_address> <amount_in_usd>`.
Requirements:
- Resolve token addresses against Velora's tokens endpoint (`/tokens/:chainId`).
- Quote with `mode=ALL` at `GET https://api.velora.xyz/v2/quote`. Always set `partner` to the bot's partner identifier (`my-app-name` is only a placeholder). Native ETH placeholder: `0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE`.
- Show the user `destAmount`, `destUSD`, `gasCostUSD`, and `priceImpact` BEFORE asking them to confirm.
- If `response.delta` exists, prefer the Delta path: build → sign EIP-712 → submit → poll. The user pays no gas.
- If only `response.market` exists, fall back to Market with `slippage=100` (1%) and warn the user about MEV exposure on larger trades (size > $5k).
- Include the `priceImpact` warning at >2%.
Reference these docs and follow them exactly:
- https://velora.xyz/docs/overview/why-velora
- https://velora.xyz/docs/api-reference/market/prices
- https://velora.xyz/docs/api-reference/market/quote
- https://velora.xyz/docs/api-reference/delta/orders-build
- https://velora.xyz/docs/api-reference/delta/orders-submit
Do NOT auto-execute trades without explicit user confirmation. Do NOT swallow Delta polling errors silently.
