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

internal/cache/backends/resp.go

@@ -44,7 +44,7 @@ type RESPWriter struct {
 
 // NewRESPWriter creates a new RESP writer from the pool (memory optimized)
 func NewRESPWriter(w io.Writer) *RESPWriter {
-	writer := writerPool.Get().(*RESPWriter)
+	writer, _ := writerPool.Get().(*RESPWriter)
 	writer.w = w
 	return writer
 }
@@ -80,7 +80,7 @@ type RESPReader struct {
 
 // NewRESPReader creates a new RESP reader from the pool (memory optimized)
 func NewRESPReader(r io.Reader) *RESPReader {
-	reader := readerPool.Get().(*RESPReader)
+	reader, _ := readerPool.Get().(*RESPReader)
 	reader.r.Reset(r)
 	return reader
 }