Closes #40

Summary

Adds automated test coverage for DebugProbe.AspNetCore middleware, rendering, configuration, and compare validation behavior.

Added Test Coverage

Middleware

• middleware execution flow
• request pipeline continuation
• ignored/debug path handling
• response stream restoration
• exception handling behavior

Request/Response Capture

• JSON request body capture
• JSON response body capture
• empty body handling
• large payload handling
• binary/non-text handling
• bounded response capture validation
• max body capture size behavior

Rendering

• details page rendering
• payload badge rendering
• HTML encoding and escaping safety

Compare Validation

• valid HTTP/HTTPS URL validation
• invalid scheme rejection
• localhost validation behavior
• local compare target option behavior

Configuration

• default options behavior
• custom option registration behavior

Additional Changes

• Add dedicated DebugProbe.AspNetCore.Tests project
• Add internal visibility for test assembly
• Add reusable test infrastructure utilities

Result

The project now validates core behavior automatically and reduces regression risk during future refactoring.