Add file logging and Discord/Slack webhook logging

[yulmwu]

New features:

• Added rotation file logging
• Added Discord/Slack webhook logging. supports background queue, batch sending, and split messages. (for rate limit/max bytes)

Discord:

Slack:

Refs: #9

[codecov]

Codecov Report

❌ Patch coverage is 76.03834% with 75 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/logging/logging.go	69.38%	37 Missing and 23 partials ⚠️
internal/http/middleware/request_logger.go	80.39%	5 Missing and 5 partials ⚠️
internal/http/router.go	0.00%	5 Missing ⚠️

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