Fix typos in Vyper contract docstrings

[Zentex1337]

Summary

Fixed typos in docstrings across all Vyper contracts:

• Fixed "conracts" to "contracts" in constructor parameter descriptions
• Fixed "valie" to "value" in exchange function parameter descriptions
• Fixed "recieve" to "receive" in exchange function parameter descriptions

These are documentation-only changes (comments/docstrings) that do not affect contract behavior.

Files affected

• All pool template contracts in contracts/pool-templates/
• All pool contracts in contracts/pools/

Test plan

• No code logic changes, docstring/comment only changes
• Contract bytecode is not affected by comment changes