Implement hypercorn-hmr: Hot Module Reloading CLI for Hypercorn

[Copilot]

This PR implements hypercorn-hmr, a drop-in replacement for hypercorn --reload that provides enhanced Hot Module Reloading (HMR) capabilities, following the same pattern as uvicorn-hmr.

Problem

Currently, hypercorn --reload restarts the entire process on every file change, which is slow and inefficient for development. This is especially problematic for applications with:

• Heavy initialization (ML models, database connections, etc.)
• Large codebases where only small changes are made
• Need for preserving application state during development

Solution

The new hypercorn-hmr package provides:

1. Fine-grained HMR: Only reloads changed modules and their dependents, not the entire process
2. Unified CLI Interface: Maintains exact same parameters as uvicorn-hmr for consistency
3. Drop-in Replacement: Can replace hypercorn --reload with faster reloading

Usage

Replace:

hypercorn app:app --reload --bind 127.0.0.1:8000

With:

hypercorn-hmr app:app --host 127.0.0.1 --port 8000

Key Features

• Consistent Interface: Same CLI parameters as uvicorn-hmr (--host, --port, --log-level, --refresh, --clear)
• HMR Integration: Uses the existing hmr package for intelligent module reloading
• Graceful Shutdown: Proper server lifecycle management with shutdown_trigger
• Browser Refresh: Optional --refresh flag for automatic page reloading (requires fastapi-reloader)

Implementation Details

• Adapts uvicorn-hmr architecture to work with Hypercorn's async serve() function
• Uses threading with proper asyncio event loop management
• Implements graceful shutdown via Hypercorn's shutdown_trigger parameter
• Maintains compatibility with existing HMR ecosystem tools

Testing

• ✅ Server starts and serves applications correctly
• ✅ File changes trigger module reloads without full restart
• ✅ API responses update immediately after code changes
• ✅ CLI interface matches uvicorn-hmr exactly
• ✅ All linting checks pass

This implementation fulfills the requirement to create a Hypercorn CLI alternative that maintains unified parameters and behavior while providing HMR capabilities.

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[hyperlint-ai-deprecated]

PR Change Summary

Implemented a Hypercorn CLI replacement with Hot Module Reload (HMR) capabilities, following the structure and behavior of uvicorn-hmr.

• Created the hypercorn-hmr package structure and added a README file.
• Implemented a main CLI script adapted from uvicorn-hmr.
• Mapped CLI arguments to maintain interface consistency with hypercorn.
• Ensured HMR functionality works correctly with hypercorn.

Added Files

• packages/hypercorn-hmr/README.md

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