Modernize Hako stack, improve coverage, and add features

[google-labs-jules]

This PR modernizes the Hako project by updating the stack, adding new features, and significantly improving test coverage.

Changes:

• Stack Modernization:
  • Updated go.mod dependencies.
  • Switched Dockerfile to a multi-stage build using golang:1.24-alpine and alpine:latest.
  • Simplified Makefile to rely on the Docker multi-stage build.
• New Features:
  • JSON Logging: Added --json flag to switch logs to JSON format using logrus.JSONFormatter.
  • Request ID: Added middleware to generate or propagate X-Request-ID.
  • Dynamic Status Code: Added support for X-Hako-Status header to override response status code.
• Test Coverage:
  • Added unit tests for request_handler.go covering status code logic and body echoing.
  • Added unit tests for Request ID middleware in middleware_test.go.
  • Added tests for JSON logging configuration in start_command_test.go.
  • Coverage for internal package improved significantly.

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PR created automatically by Jules for task 15989753023545738018 started by @sha1n

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[github-actions]

Pull Request Test Coverage Report for Build 21118746274

Details

• 32 of 36 (88.89%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+3.1%) to 67.913%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/start_command.go	13	17	76.47%

Totals
Change from base Build 20141117328:	3.1%
Covered Lines:	218
Relevant Lines:	321

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💛 - Coveralls