feat(basectl): automatic devnet detection

[danyalprout]

Description

Update basectl so that when -c devnet is passed, it attempts to auto-resolve devnet settings from the current base/base directory (via. the .devnet folder).

[0xEdmundo]

Hi! I'd like to work on this issue. Could you please assign it to me?

I'm planning to:

1. Detect when -c devnet is passed to basectl
2. Auto-resolve devnet settings from the .devnet folder in the current base/base directory
3. Add tests for the new functionality

Looking forward to contributing!

[danyalprout]

@0xEdmundo all yours. You can test against our devnet, which you can stat by running just devnet in the base/base repo (see here).

[0xEdmundo]

@danyalprout

I just submitted PR #35
to address this issue.

Implementation summary:

• Added [find_devnet_config()] function that searches for .devnet/basectl.yaml starting from current directory and traversing parent directories
• Updated ChainConfig::load() to handle the "devnet" case
• Added test for the not found error case

The PR is ready for review. Please let me know if any changes are needed