perf: optimize 404/405 handling with pre-encoded responses and lazy l…

[alexferl]

…ogging

• Pre-encode JSON error responses at init time to avoid repeated encoding
• Add lazy request ID generation - only generated when logging is enabled
• Use pre-encoded plain text for default 404/405 handlers (faster than ProblemDetail)
• Add shouldLogRequest() helper to respect DisableDefaultMiddlewares setting

Also fixes RequestLogger.Enabled to use *bool so users can explicitly disable logging with config.Bool(false).

[coveralls]

Pull Request Test Coverage Report for Build 22976467627

Details

• 70 of 72 (97.22%) changed or added relevant lines in 2 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.01%) to 93.44%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
router.go	67	69	97.1%

Files with Coverage Reduction	New Missed Lines	%
server_tls.go	5	87.63%

Totals
Change from base Build 22936107910:	0.01%
Covered Lines:	8361
Relevant Lines:	8948

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💛 - Coveralls