feat(instructions): add Symfony/PHP development instructions

docs/README.instructions.md

@@ -149,6 +149,7 @@ Team and project-specific instructions to enhance GitHub Copilot's behavior for
 | [Style Components with Modern Theming (Preview)](../instructions/pcf-fluent-modern-theming.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fpcf-fluent-modern-theming.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fpcf-fluent-modern-theming.instructions.md) | Style components with modern theming using Fluent UI |
 | [Svelte 5 and SvelteKit Development Instructions](../instructions/svelte.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fsvelte.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fsvelte.instructions.md) | Svelte 5 and SvelteKit development standards and best practices for component-based user interfaces and full-stack applications |
 | [Swift MCP Server Development Guidelines](../instructions/swift-mcp-server.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fswift-mcp-server.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fswift-mcp-server.instructions.md) | Best practices and patterns for building Model Context Protocol (MCP) servers in Swift using the official MCP Swift SDK package. |
+| [Symfony Development Instructions](../instructions/php-symfony.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fphp-symfony.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Fphp-symfony.instructions.md) | Symfony development standards aligned with official Symfony Best Practices |
 | [Taming Copilot](../instructions/taming-copilot.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftaming-copilot.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftaming-copilot.instructions.md) | Prevent Copilot from wreaking havoc across your codebase, keeping it under control. |
 | [TanStack Start with Shadcn/ui Development Guide](../instructions/tanstack-start-shadcn-tailwind.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftanstack-start-shadcn-tailwind.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftanstack-start-shadcn-tailwind.instructions.md) | Guidelines for building TanStack Start applications |
 | [Task Plan Implementation Instructions](../instructions/task-implementation.instructions.md)<br />[![Install in VS Code](https://img.shields.io/badge/VS_Code-Install-0098FF?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftask-implementation.instructions.md)<br />[![Install in VS Code Insiders](https://img.shields.io/badge/VS_Code_Insiders-Install-24bfa5?style=flat-square&logo=visualstudiocode&logoColor=white)](https://aka.ms/awesome-copilot/install/instructions?url=vscode-insiders%3Achat-instructions%2Finstall%3Furl%3Dhttps%3A%2F%2Fraw.githubusercontent.com%2Fgithub%2Fawesome-copilot%2Fmain%2Finstructions%2Ftask-implementation.instructions.md) | Instructions for implementing task plans with progressive tracking and change record - Brought to you by microsoft/edge-ai |

instructions/php-symfony.instructions.md

@@ -0,0 +1,122 @@
+---
+description: "Symfony development standards aligned with official Symfony Best Practices"
+applyTo: "**/*.php, **/*.yaml, **/*.yml, **/*.xml, **/*.twig"
+---
+
+# Symfony Development Instructions
+
+Instructions for developing Symfony applications following the official Symfony Best Practices and core framework philosophy.
+
+## Project Context
+- Symfony (latest stable or LTS)
+- Default Symfony directory structure
+- Autowiring and autoconfiguration enabled
+- Doctrine ORM when persistence is needed
+- Twig for templating
+- Symfony Forms, Validator, Security, Messenger as needed
+- PHPUnit for testing
+- Attribute-based configuration where supported
+
+## Project Structure
+- Use the default Symfony directory structure
+- Do not create bundles for application code
+- Organize application code using PHP namespaces
+- Keep configuration in `config/`, application code in `src/`, templates in `templates/`
+
+## Configuration
+
+### Environment Configuration
+- Use environment variables for infrastructure-related configuration
+- Use `.env` files to define environment-specific values
+- Do not use environment variables to control application behavior
+
+### Sensitive Configuration
+- Store secrets (API keys, credentials) using Symfony Secrets
+- Never commit secrets to the repository
+
+### Application Configuration
+- Use parameters in `config/services.yaml` for application behavior configuration
+- Override parameters per environment only when needed
+- Prefix parameters with `app.` to avoid collisions
+- Use short, descriptive parameter names
+- Use PHP constants for configuration values that rarely change
+
+## Services & Dependency Injection
+- Use dependency injection exclusively
+- Prefer constructor injection
+- Use autowiring and autoconfiguration by default
+- Keep services private whenever possible
+- Avoid accessing services via `$container->get()`
+- Use YAML as the preferred format for service configuration
+- Use interfaces where it improves decoupling or clarity
+
+## Controllers
+- Extend `AbstractController`
+- Keep controllers thin and focused on glue code
+- Do not place business logic in controllers
+- Use attributes to configure routing, caching, and security
+- Use dependency injection for services
+- Use Entity Value Resolvers when convenient and appropriate
+- Perform complex queries explicitly via repositories when needed
+
+## Doctrine & Persistence
+- Use Doctrine entities as plain PHP objects
+- Define Doctrine mapping using PHP attributes
+- Use repositories for querying data
+- Avoid putting business logic in repositories
+- Use migrations for all schema changes
+
+## Templates (Twig)
+- Use snake_case for template names, directories, and variables
+- Prefix template fragments with an underscore
+- Keep templates focused on presentation
+- Avoid business logic in Twig templates
+- Escape output by default
+- Avoid using `|raw` unless content is trusted and sanitized
+
+## Forms
+- Define forms as PHP classes
+- Do not build forms directly in controllers
+- Add form buttons in templates, not in form classes
+- Define validation constraints on the underlying object
+- Use a single controller action to render and process each form
+- Define submit buttons in controllers only when multiple submits are required
+
+## Validation
+- Use Symfony Validator constraints
+- Validate data at application boundaries
+- Prefer object-level validation over form-only validation when reuse is needed
+
+## Internationalization
+- Use XLIFF for translation files
+- Use translation keys instead of literal content strings
+- Use descriptive keys that express purpose, not location
+
+## Security
+- Prefer a single firewall unless multiple systems are required
+- Use the auto password hasher
+- Use voters for complex authorization logic
+- Avoid complex security expressions in attributes
+
+## Web Assets
+- Use AssetMapper to manage web assets
+- Avoid unnecessary frontend build complexity unless required
+
+## Asynchronous Processing
+- Use Symfony Messenger for async and background tasks
+- Keep message handlers small and focused
+- Configure failure transports for failed messages
+
+## Testing
+- Write functional tests using `WebTestCase`
+- Add smoke tests to ensure all public URLs respond successfully
+- Hard-code URLs in functional tests instead of generating routes
+- Use unit tests where appropriate for isolated logic
+- Add more specific tests incrementally as the application evolves
+
+## General Guidelines
+- Prefer clarity over abstraction
+- Follow Symfony conventions before introducing custom patterns
+- Keep configuration explicit and readable
+- Avoid premature optimization
+- Use Symfony Demo as a reference implementation