[Feature] Unified proxy response structure to standardize API responses

[Issac-Newton]

Problem Statement

The current sandbox proxy responses lack a consistent structure making integration difficult. The different endpoints return different response structures which complicates client-side handling.

Proposed Solution

Standardize all API responses to follow consistent structure as described in the new interface response body specification:

• A standardized response wrapper (BaseResponse with status, message, error fields)
• Consistent result objects containing code and failure_reason
• Proper inheritance hierarchy for all response type classes

Changes Made

• Created specification document at docs/_specs/response/interface_response_body_spec.md
• Refactored response classes in rock/actions/sandbox/response.py to inherit from SandboxResponse
• Added code and failure_reason fields to all response types
• Updated API endpoint responses to use the RockResponse[SpecificResponseType] wrapper
• Added tests in tests/unit/test_sandbox_response.py to validate compliance
• Moved interface specification file to proper location for documentation organization

Benefits

• Consistent API response format makes integration easier
• Clear documentation of response structures
• Better error handling with standardized error fields
• Improved API predictability

Component Affected

• Sandbox
• Actions
• SDK & API
• Documentation & Examples