app start control

[richardelms]

Goal

Adds a new mechanism to control the “app start” span by exposing a public API for querying and manipulating that span.

Changeset

Introduces IAppStartSpanControl interface and SpanType query objects.
Registers a SpanControlRegistry at startup and exposes GetSpanControl<T> in BugsnagPerformance.
Implements AppStartSpanControl and wires it through AppStartHandler to the public API.

Testing

Added E2E tests

[bugsnagbot]

Build size impact

Format	Size impact of Bugsnag (kB)
IL2CPP APK	2.38
IL2CPP IPA	2.69

Generated by 🚫 Danger

[Copilot]

Pull Request Overview

This PR introduces a new public API for controlling and customizing the "app start" span in the performance monitoring system. It allows developers to query and manipulate app start spans at runtime through a structured interface.

• Adds IAppStartSpanControl interface with methods to set and clear span types
• Implements a SpanControlRegistry system for managing different span control types
• Exposes GetSpanControl<T> method in the public BugsnagPerformance API

Reviewed Changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
SpanControl.cs	Defines public interfaces and query objects for span control
BugsnagPerformance.cs	Adds GetSpanControl method and registers SpanControlRegistry
SpanControlRegistry.cs	Internal registry that maps queries to span control implementations
AppStartSpanControl.cs	Implementation of IAppStartSpanControl for app start span manipulation
AppStartHandler.cs	Exposes GetAppStartSpan method for registry access
Test scenarios	Adds test cases for span customization and clearing functionality
CHANGELOG.md	Documents the new feature addition