Add GitHub Copilot instructions for efficient MSAL Android development

[Copilot]

This PR adds a comprehensive .github/copilot-instructions.md file to onboard GitHub Copilot coding agents to the MSAL Android repository. The instructions are designed to significantly improve the quality and efficiency of AI-generated code by providing essential guidance on repository structure, build system, and MSAL-specific patterns.

What's Added

The new copilot instructions file provides:

Repository Navigation & Structure

• Clear overview of the multi-module Android project structure
• Key file locations and their purposes
• References to existing AI guidance (Ai.md, .clinerules/)

Build System Understanding

• Safe build commands and prerequisite checks
• Common build failure patterns and solutions
• Module-specific testing strategies

MSAL-Specific Debugging Patterns

• Common API misuse patterns with correct implementations
• Authentication debugging checklist
• Configuration validation guidelines
• URL encoding requirements (AndroidManifest vs auth_config.json)

Code Quality Guidelines

• Required coding patterns and standards
• Resource management best practices
• Error handling patterns
• Performance considerations

Goals Achieved

This addresses the repository onboarding requirements by:

1. Reducing CI build failures - Provides safe build commands and common failure solutions
2. Minimizing bash command failures - Includes prerequisite checks and validated commands
3. Reducing exploration overhead - Clear navigation guide and file location references
4. Enabling better debugging - Specific patterns for MSAL API misuse detection

Integration with Existing AI Resources

The instructions complement rather than replace existing documentation:

• References the comprehensive Ai.md guide
• Points to detailed .clinerules/msal-cline-rules.md
• Mentions the fadi/copilot-1 branch for additional sample app guidance
• Maintains focus on debugging and build system specifics

The file is concise at 186 lines (well under the 2-page limit) while providing maximum practical value for coding agents working on this repository for the first time.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dl.google.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED --add-opens=java.xml/javax.xml.namespace=ALL-UNNAMED -XX:MaxMetaspaceSize=512m -XX:+HeapDumpOnOutOfMemoryError -Xmx2048m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.11.1-all/2qik7nd48slq1ooc2496ixf4i/gradle-8.11.1/lib/gradle-daemon-main-8.11.1.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.11.1-all/2qik7nd48slq1ooc2496ixf4i/gradle-8.11.1/lib/agents/gradle-instrumentation-agent-8.11.1.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.11.1 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.