Implement `NotFoundError`

[codebestia]

Description

Raised on HTTP 404 responses. Should include the resource type and ID that was not found, so the developer can distinguish a missing payment from a missing invoice without parsing the message string.

Proposed Steps

• Define NotFoundError(ShadeError) in errors.py.
• Add resource_type: Optional[str] and resource_id: Optional[str] attributes.
• Populate from the 404 response body.

Acceptance Criteria

• A 404 response raises NotFoundError.
• error.resource_type and error.resource_id reflect the queried resource.
• Subclasses ShadeError.

[Enemuo-debug]

Can I please be opportuned to work on this??

[xJeffx23]

Hello!

My name is Jefferson, and I have been contributing to open-source projects for over a year. I have participated in multiple hackathons and have experience working with SDKs, API integrations, and developer-focused tooling.

I would like to work on this issue because structured error handling significantly improves the developer experience. Providing resource-specific information through a dedicated NotFoundError would make debugging easier and eliminate the need to parse error message strings to determine which resource was missing.

My plan would be to introduce a NotFoundError class inheriting from ShadeError, populate the resource_type and resource_id fields from the API response payload, update the 404 handling logic accordingly, and add tests to verify the correct exception type and metadata are exposed to SDK consumers.

I would greatly appreciate the opportunity to contribute to the project. Thank you for your time and consideration!