Parent Issue

Closes #406

Summary

Implement the main http2_server class for accepting and handling HTTP/2 connections.

Tasks

• Create include/kcenon/network/protocols/http2/http2_server.h
• Create src/protocols/http2/http2_server.cpp
• Implement connection acceptance
• Implement server-side handshake (SETTINGS exchange)
• Implement request parsing from HEADERS frames
• Add flow control handling
• Add HPACK integration for server
• TLS/ALPN configuration for server

Files to Create

• include/kcenon/network/protocols/http2/http2_server.h
• src/protocols/http2/http2_server.cpp

Acceptance Criteria

• Server accepts HTTP/2 connections
• Proper SETTINGS exchange
• Request handling with callback API
• Stream multiplexing works
• Flow control respected
• TLS with ALPN works