feat(core): refactor linters config and improve code quality (#119)

- [x] Reorganize golangci-lint configuration with documented disable reasons
- [x] Simplify errcheck and revive linter rules with targeted exclusions
- [x] Pre-compile regex patterns in input_validation.go for performance
- [x] Fix type assertions in memory_shard.go and resp.go with safety checks
- [x] Replace string comparison with EqualFold for case-insensitive matching
- [x] Fix loop variable captures in jwk.go and logout.go
- [x] Change high goroutine log level from Info to Debug in autocleanup.go
- [x] Replace deprecated "cancelled" spelling with "canceled" throughout
- [x] Add nolint annotations for intentional unused parameters
- [x] Improve comment formatting for deprecated functions
- [x] Fix comment spelling: "marshalling" → "marshaling"
- [x] Refactor provider warnings formatting in internal/providers/warnings.go
- [x] Simplify metrics summary building in internal/recovery/metrics.go
- [x] Pre-allocate slice in error_recovery.go GetDegradedServices
- [x] Refactor context cancellation checks in redis.go

autocleanup.go

@@ -599,8 +599,9 @@ func GetGlobalTaskMemoryMonitor(logger *Logger) *TaskMemoryMonitor {
 	return globalTaskMemoryMonitor
 }
 
-// NewTaskMemoryMonitor creates a new memory monitor for task registry
-// Deprecated: Use GetGlobalTaskMemoryMonitor instead for singleton behavior
+// NewTaskMemoryMonitor creates a new memory monitor for task registry.
+//
+// Deprecated: Use GetGlobalTaskMemoryMonitor instead for singleton behavior.
 func NewTaskMemoryMonitor(logger *Logger, registry *TaskRegistry) *TaskMemoryMonitor {
 	return GetGlobalTaskMemoryMonitor(logger)
 }
@@ -712,7 +713,7 @@ func (mm *TaskMemoryMonitor) checkForMemoryIssues(stats TaskMemoryStats) {
 
 	// Check for goroutine leaks (arbitrary threshold)
 	if stats.Goroutines > 100 {
-		mm.logger.Infof("High goroutine count detected: %d", stats.Goroutines)
+		mm.logger.Debugf("High goroutine count detected: %d", stats.Goroutines)
 	}
 
 	// Check for heap growth without corresponding GC activity