chore: modernize workflows, security scanning, and linting configuration (#50)

* build: update Go 1.25, CI workflows, and build tooling

- Upgrade to Go 1.25
- Add benchmark targets to Makefile
- Implement parallel gosec execution
- Lock tool versions for reproducibility
- Add shellcheck directives to scripts
- Update CI workflows with improved caching

* refactor: migrate from golangci-lint to revive

- Replace golangci-lint with revive for linting
- Configure comprehensive revive rules
- Fix all EditorConfig violations
- Add yamllint and yamlfmt support
- Remove deprecated .golangci.yml

* refactor: rename utils to shared and deduplicate code

- Rename utils package to shared
- Add shared constants package
- Deduplicate constants across packages
- Address CodeRabbit review feedback

* fix: resolve SonarQube issues and add safety guards

- Fix all 73 SonarQube OPEN issues
- Add nil guards for resourceMonitor, backpressure, metricsCollector
- Implement io.Closer for headerFileReader
- Propagate errors from processing helpers
- Add metrics and templates packages
- Improve error handling across codebase

* test: improve test infrastructure and coverage

- Add benchmarks for cli, fileproc, metrics
- Improve test coverage for cli, fileproc, config
- Refactor tests with helper functions
- Add shared test constants
- Fix test function naming conventions
- Reduce cognitive complexity in benchmark tests

* docs: update documentation and configuration examples

- Update CLAUDE.md with current project state
- Refresh README with new features
- Add usage and configuration examples
- Add SonarQube project configuration
- Consolidate config.example.yaml

* fix: resolve shellcheck warnings in scripts

- Use ./*.go instead of *.go to prevent dash-prefixed filenames
  from being interpreted as options (SC2035)
- Remove unreachable return statement after exit (SC2317)
- Remove obsolete gibidiutils/ directory reference

* chore(deps): upgrade go dependencies

* chore(lint): megalinter fixes

* fix: improve test coverage and fix file descriptor leaks

- Add defer r.Close() to fix pipe file descriptor leaks in benchmark tests
- Refactor TestProcessorConfigureFileTypes with helper functions and assertions
- Refactor TestProcessorLogFinalStats with output capture and keyword verification
- Use shared constants instead of literal strings (TestFilePNG, FormatMarkdown, etc.)
- Reduce cognitive complexity by extracting helper functions

* fix: align test comments with function names

Remove underscores from test comments to match actual function names:
- benchmark/benchmark_test.go (2 fixes)
- fileproc/filetypes_config_test.go (4 fixes)
- fileproc/filetypes_registry_test.go (6 fixes)
- fileproc/processor_test.go (6 fixes)
- fileproc/resource_monitor_types_test.go (4 fixes)
- fileproc/writer_test.go (3 fixes)

* fix: various test improvements and bug fixes

- Remove duplicate maxCacheSize check in filetypes_registry_test.go
- Shorten long comment in processor_test.go to stay under 120 chars
- Remove flaky time.Sleep in collector_test.go, use >= 0 assertion
- Close pipe reader in benchmark_test.go to fix file descriptor leak
- Use ContinueOnError in flags_test.go to match ResetFlags behavior
- Add nil check for p.ui in processor_workers.go before UpdateProgress
- Fix resource_monitor_validation_test.go by setting hardMemoryLimitBytes directly

* chore(yaml): add missing document start markers

Add --- document start to YAML files to satisfy yamllint:
- .github/workflows/codeql.yml
- .github/workflows/build-test-publish.yml
- .github/workflows/security.yml
- .github/actions/setup/action.yml

* fix: guard nil resourceMonitor and fix test deadlock

- Guard resourceMonitor before CreateFileProcessingContext call
- Add ui.UpdateProgress on emergency stop and path error returns
- Fix potential deadlock in TestProcessFile using wg.Go with defer close

config/getters.go

@@ -1,157 +1,331 @@
+// Package config handles application configuration management.
 package config
 
 import (
 	"strings"
 
 	"github.com/spf13/viper"
+
+	"github.com/ivuorinen/gibidify/shared"
 )
 
-// GetFileSizeLimit returns the file size limit from configuration.
-func GetFileSizeLimit() int64 {
-	return viper.GetInt64("fileSizeLimit")
+// FileSizeLimit returns the file size limit from configuration.
+// Default: ConfigFileSizeLimitDefault (5MB).
+func FileSizeLimit() int64 {
+	return viper.GetInt64(shared.ConfigKeyFileSizeLimit)
 }
 
-// GetIgnoredDirectories returns the list of directories to ignore.
-func GetIgnoredDirectories() []string {
-	return viper.GetStringSlice("ignoreDirectories")
+// IgnoredDirectories returns the list of directories to ignore.
+// Default: ConfigIgnoredDirectoriesDefault.
+func IgnoredDirectories() []string {
+	return viper.GetStringSlice(shared.ConfigKeyIgnoreDirectories)
 }
 
-// GetMaxConcurrency returns the maximum concurrency level.
-func GetMaxConcurrency() int {
-	return viper.GetInt("maxConcurrency")
+// MaxConcurrency returns the maximum concurrency level.
+// Returns 0 if not set (caller should determine appropriate default).
+func MaxConcurrency() int {
+	return viper.GetInt(shared.ConfigKeyMaxConcurrency)
 }
 
-// GetSupportedFormats returns the list of supported output formats.
-func GetSupportedFormats() []string {
-	return viper.GetStringSlice("supportedFormats")
+// SupportedFormats returns the list of supported output formats.
+// Returns empty slice if not set.
+func SupportedFormats() []string {
+	return viper.GetStringSlice(shared.ConfigKeySupportedFormats)
 }
 
-// GetFilePatterns returns the list of file patterns.
-func GetFilePatterns() []string {
-	return viper.GetStringSlice("filePatterns")
+// FilePatterns returns the list of file patterns.
+// Returns empty slice if not set.
+func FilePatterns() []string {
+	return viper.GetStringSlice(shared.ConfigKeyFilePatterns)
 }
 
 // IsValidFormat checks if the given format is valid.
 func IsValidFormat(format string) bool {
 	format = strings.ToLower(strings.TrimSpace(format))
 	supportedFormats := map[string]bool{
-		"json":     true,
-		"yaml":     true,
-		"markdown": true,
+		shared.FormatJSON:     true,
+		shared.FormatYAML:     true,
+		shared.FormatMarkdown: true,
 	}
+
 	return supportedFormats[format]
 }
 
-// GetFileTypesEnabled returns whether file types are enabled.
-func GetFileTypesEnabled() bool {
-	return viper.GetBool("fileTypes.enabled")
+// FileTypesEnabled returns whether file types are enabled.
+// Default: ConfigFileTypesEnabledDefault (true).
+func FileTypesEnabled() bool {
+	return viper.GetBool(shared.ConfigKeyFileTypesEnabled)
 }
 
-// GetCustomImageExtensions returns custom image extensions.
-func GetCustomImageExtensions() []string {
-	return viper.GetStringSlice("fileTypes.customImageExtensions")
+// CustomImageExtensions returns custom image extensions.
+// Default: ConfigCustomImageExtensionsDefault (empty).
+func CustomImageExtensions() []string {
+	return viper.GetStringSlice(shared.ConfigKeyFileTypesCustomImageExtensions)
 }
 
-// GetCustomBinaryExtensions returns custom binary extensions.
-func GetCustomBinaryExtensions() []string {
-	return viper.GetStringSlice("fileTypes.customBinaryExtensions")
+// CustomBinaryExtensions returns custom binary extensions.
+// Default: ConfigCustomBinaryExtensionsDefault (empty).
+func CustomBinaryExtensions() []string {
+	return viper.GetStringSlice(shared.ConfigKeyFileTypesCustomBinaryExtensions)
 }
 
-// GetCustomLanguages returns custom language mappings.
-func GetCustomLanguages() map[string]string {
-	return viper.GetStringMapString("fileTypes.customLanguages")
+// CustomLanguages returns custom language mappings.
+// Default: ConfigCustomLanguagesDefault (empty).
+func CustomLanguages() map[string]string {
+	return viper.GetStringMapString(shared.ConfigKeyFileTypesCustomLanguages)
 }
 
-// GetDisabledImageExtensions returns disabled image extensions.
-func GetDisabledImageExtensions() []string {
-	return viper.GetStringSlice("fileTypes.disabledImageExtensions")
+// DisabledImageExtensions returns disabled image extensions.
+// Default: ConfigDisabledImageExtensionsDefault (empty).
+func DisabledImageExtensions() []string {
+	return viper.GetStringSlice(shared.ConfigKeyFileTypesDisabledImageExtensions)
 }
 
-// GetDisabledBinaryExtensions returns disabled binary extensions.
-func GetDisabledBinaryExtensions() []string {
-	return viper.GetStringSlice("fileTypes.disabledBinaryExtensions")
+// DisabledBinaryExtensions returns disabled binary extensions.
+// Default: ConfigDisabledBinaryExtensionsDefault (empty).
+func DisabledBinaryExtensions() []string {
+	return viper.GetStringSlice(shared.ConfigKeyFileTypesDisabledBinaryExtensions)
 }
 
-// GetDisabledLanguageExtensions returns disabled language extensions.
-func GetDisabledLanguageExtensions() []string {
-	return viper.GetStringSlice("fileTypes.disabledLanguageExtensions")
+// DisabledLanguageExtensions returns disabled language extensions.
+// Default: ConfigDisabledLanguageExtensionsDefault (empty).
+func DisabledLanguageExtensions() []string {
+	return viper.GetStringSlice(shared.ConfigKeyFileTypesDisabledLanguageExts)
 }
 
 // Backpressure getters
 
-// GetBackpressureEnabled returns whether backpressure is enabled.
-func GetBackpressureEnabled() bool {
-	return viper.GetBool("backpressure.enabled")
+// BackpressureEnabled returns whether backpressure is enabled.
+// Default: ConfigBackpressureEnabledDefault (true).
+func BackpressureEnabled() bool {
+	return viper.GetBool(shared.ConfigKeyBackpressureEnabled)
 }
 
-// GetMaxPendingFiles returns the maximum pending files.
-func GetMaxPendingFiles() int {
-	return viper.GetInt("backpressure.maxPendingFiles")
+// MaxPendingFiles returns the maximum pending files.
+// Default: ConfigMaxPendingFilesDefault (1000).
+func MaxPendingFiles() int {
+	return viper.GetInt(shared.ConfigKeyBackpressureMaxPendingFiles)
 }
 
-// GetMaxPendingWrites returns the maximum pending writes.
-func GetMaxPendingWrites() int {
-	return viper.GetInt("backpressure.maxPendingWrites")
+// MaxPendingWrites returns the maximum pending writes.
+// Default: ConfigMaxPendingWritesDefault (100).
+func MaxPendingWrites() int {
+	return viper.GetInt(shared.ConfigKeyBackpressureMaxPendingWrites)
 }
 
-// GetMaxMemoryUsage returns the maximum memory usage.
-func GetMaxMemoryUsage() int64 {
-	return viper.GetInt64("backpressure.maxMemoryUsage")
+// MaxMemoryUsage returns the maximum memory usage.
+// Default: ConfigMaxMemoryUsageDefault (100MB).
+func MaxMemoryUsage() int64 {
+	return viper.GetInt64(shared.ConfigKeyBackpressureMaxMemoryUsage)
 }
 
-// GetMemoryCheckInterval returns the memory check interval.
-func GetMemoryCheckInterval() int {
-	return viper.GetInt("backpressure.memoryCheckInterval")
+// MemoryCheckInterval returns the memory check interval.
+// Default: ConfigMemoryCheckIntervalDefault (1000 files).
+func MemoryCheckInterval() int {
+	return viper.GetInt(shared.ConfigKeyBackpressureMemoryCheckInt)
 }
 
 // Resource limits getters
 
-// GetResourceLimitsEnabled returns whether resource limits are enabled.
-func GetResourceLimitsEnabled() bool {
-	return viper.GetBool("resourceLimits.enabled")
+// ResourceLimitsEnabled returns whether resource limits are enabled.
+// Default: ConfigResourceLimitsEnabledDefault (true).
+func ResourceLimitsEnabled() bool {
+	return viper.GetBool(shared.ConfigKeyResourceLimitsEnabled)
 }
 
-// GetMaxFiles returns the maximum number of files.
-func GetMaxFiles() int {
-	return viper.GetInt("resourceLimits.maxFiles")
+// MaxFiles returns the maximum number of files.
+// Default: ConfigMaxFilesDefault (10000).
+func MaxFiles() int {
+	return viper.GetInt(shared.ConfigKeyResourceLimitsMaxFiles)
 }
 
-// GetMaxTotalSize returns the maximum total size.
-func GetMaxTotalSize() int64 {
-	return viper.GetInt64("resourceLimits.maxTotalSize")
+// MaxTotalSize returns the maximum total size.
+// Default: ConfigMaxTotalSizeDefault (1GB).
+func MaxTotalSize() int64 {
+	return viper.GetInt64(shared.ConfigKeyResourceLimitsMaxTotalSize)
 }
 
-// GetFileProcessingTimeoutSec returns the file processing timeout in seconds.
-func GetFileProcessingTimeoutSec() int {
-	return viper.GetInt("resourceLimits.fileProcessingTimeoutSec")
+// FileProcessingTimeoutSec returns the file processing timeout in seconds.
+// Default: ConfigFileProcessingTimeoutSecDefault (30 seconds).
+func FileProcessingTimeoutSec() int {
+	return viper.GetInt(shared.ConfigKeyResourceLimitsFileProcessingTO)
 }
 
-// GetOverallTimeoutSec returns the overall timeout in seconds.
-func GetOverallTimeoutSec() int {
-	return viper.GetInt("resourceLimits.overallTimeoutSec")
+// OverallTimeoutSec returns the overall timeout in seconds.
+// Default: ConfigOverallTimeoutSecDefault (3600 seconds).
+func OverallTimeoutSec() int {
+	return viper.GetInt(shared.ConfigKeyResourceLimitsOverallTO)
 }
 
-// GetMaxConcurrentReads returns the maximum concurrent reads.
-func GetMaxConcurrentReads() int {
-	return viper.GetInt("resourceLimits.maxConcurrentReads")
+// MaxConcurrentReads returns the maximum concurrent reads.
+// Default: ConfigMaxConcurrentReadsDefault (10).
+func MaxConcurrentReads() int {
+	return viper.GetInt(shared.ConfigKeyResourceLimitsMaxConcurrentReads)
 }
 
-// GetRateLimitFilesPerSec returns the rate limit files per second.
-func GetRateLimitFilesPerSec() int {
-	return viper.GetInt("resourceLimits.rateLimitFilesPerSec")
+// RateLimitFilesPerSec returns the rate limit files per second.
+// Default: ConfigRateLimitFilesPerSecDefault (0 = disabled).
+func RateLimitFilesPerSec() int {
+	return viper.GetInt(shared.ConfigKeyResourceLimitsRateLimitFilesPerSec)
 }
 
-// GetHardMemoryLimitMB returns the hard memory limit in MB.
-func GetHardMemoryLimitMB() int {
-	return viper.GetInt("resourceLimits.hardMemoryLimitMB")
+// HardMemoryLimitMB returns the hard memory limit in MB.
+// Default: ConfigHardMemoryLimitMBDefault (512MB).
+func HardMemoryLimitMB() int {
+	return viper.GetInt(shared.ConfigKeyResourceLimitsHardMemoryLimitMB)
 }
 
-// GetEnableGracefulDegradation returns whether graceful degradation is enabled.
-func GetEnableGracefulDegradation() bool {
-	return viper.GetBool("resourceLimits.enableGracefulDegradation")
+// EnableGracefulDegradation returns whether graceful degradation is enabled.
+// Default: ConfigEnableGracefulDegradationDefault (true).
+func EnableGracefulDegradation() bool {
+	return viper.GetBool(shared.ConfigKeyResourceLimitsEnableGracefulDeg)
 }
 
-// GetEnableResourceMonitoring returns whether resource monitoring is enabled.
-func GetEnableResourceMonitoring() bool {
-	return viper.GetBool("resourceLimits.enableResourceMonitoring")
+// EnableResourceMonitoring returns whether resource monitoring is enabled.
+// Default: ConfigEnableResourceMonitoringDefault (true).
+func EnableResourceMonitoring() bool {
+	return viper.GetBool(shared.ConfigKeyResourceLimitsEnableMonitoring)
+}
+
+// Template system getters
+
+// OutputTemplate returns the selected output template name.
+// Default: ConfigOutputTemplateDefault (empty string).
+func OutputTemplate() string {
+	return viper.GetString(shared.ConfigKeyOutputTemplate)
+}
+
+// metadataBool is a helper for metadata boolean configuration values.
+// All metadata flags default to false.
+func metadataBool(key string) bool {
+	return viper.GetBool("output.metadata." + key)
+}
+
+// TemplateMetadataIncludeStats returns whether to include stats in metadata.
+func TemplateMetadataIncludeStats() bool {
+	return metadataBool("includeStats")
+}
+
+// TemplateMetadataIncludeTimestamp returns whether to include timestamp in metadata.
+func TemplateMetadataIncludeTimestamp() bool {
+	return metadataBool("includeTimestamp")
+}
+
+// TemplateMetadataIncludeFileCount returns whether to include file count in metadata.
+func TemplateMetadataIncludeFileCount() bool {
+	return metadataBool("includeFileCount")
+}
+
+// TemplateMetadataIncludeSourcePath returns whether to include source path in metadata.
+func TemplateMetadataIncludeSourcePath() bool {
+	return metadataBool("includeSourcePath")
+}
+
+// TemplateMetadataIncludeFileTypes returns whether to include file types in metadata.
+func TemplateMetadataIncludeFileTypes() bool {
+	return metadataBool("includeFileTypes")
+}
+
+// TemplateMetadataIncludeProcessingTime returns whether to include processing time in metadata.
+func TemplateMetadataIncludeProcessingTime() bool {
+	return metadataBool("includeProcessingTime")
+}
+
+// TemplateMetadataIncludeTotalSize returns whether to include total size in metadata.
+func TemplateMetadataIncludeTotalSize() bool {
+	return metadataBool("includeTotalSize")
+}
+
+// TemplateMetadataIncludeMetrics returns whether to include metrics in metadata.
+func TemplateMetadataIncludeMetrics() bool {
+	return metadataBool("includeMetrics")
+}
+
+// markdownBool is a helper for markdown boolean configuration values.
+// All markdown flags default to false.
+func markdownBool(key string) bool {
+	return viper.GetBool("output.markdown." + key)
+}
+
+// TemplateMarkdownUseCodeBlocks returns whether to use code blocks in markdown.
+func TemplateMarkdownUseCodeBlocks() bool {
+	return markdownBool("useCodeBlocks")
+}
+
+// TemplateMarkdownIncludeLanguage returns whether to include language in code blocks.
+func TemplateMarkdownIncludeLanguage() bool {
+	return markdownBool("includeLanguage")
+}
+
+// TemplateMarkdownHeaderLevel returns the header level for file sections.
+// Default: ConfigMarkdownHeaderLevelDefault (0).
+func TemplateMarkdownHeaderLevel() int {
+	return viper.GetInt(shared.ConfigKeyOutputMarkdownHeaderLevel)
+}
+
+// TemplateMarkdownTableOfContents returns whether to include table of contents.
+func TemplateMarkdownTableOfContents() bool {
+	return markdownBool("tableOfContents")
+}
+
+// TemplateMarkdownUseCollapsible returns whether to use collapsible sections.
+func TemplateMarkdownUseCollapsible() bool {
+	return markdownBool("useCollapsible")
+}
+
+// TemplateMarkdownSyntaxHighlighting returns whether to enable syntax highlighting.
+func TemplateMarkdownSyntaxHighlighting() bool {
+	return markdownBool("syntaxHighlighting")
+}
+
+// TemplateMarkdownLineNumbers returns whether to include line numbers.
+func TemplateMarkdownLineNumbers() bool {
+	return markdownBool("lineNumbers")
+}
+
+// TemplateMarkdownFoldLongFiles returns whether to fold long files.
+func TemplateMarkdownFoldLongFiles() bool {
+	return markdownBool("foldLongFiles")
+}
+
+// TemplateMarkdownMaxLineLength returns the maximum line length.
+// Default: ConfigMarkdownMaxLineLengthDefault (0 = unlimited).
+func TemplateMarkdownMaxLineLength() int {
+	return viper.GetInt(shared.ConfigKeyOutputMarkdownMaxLineLen)
+}
+
+// TemplateCustomCSS returns custom CSS for markdown output.
+// Default: ConfigMarkdownCustomCSSDefault (empty string).
+func TemplateCustomCSS() string {
+	return viper.GetString(shared.ConfigKeyOutputMarkdownCustomCSS)
+}
+
+// TemplateCustomHeader returns custom header template.
+// Default: ConfigCustomHeaderDefault (empty string).
+func TemplateCustomHeader() string {
+	return viper.GetString(shared.ConfigKeyOutputCustomHeader)
+}
+
+// TemplateCustomFooter returns custom footer template.
+// Default: ConfigCustomFooterDefault (empty string).
+func TemplateCustomFooter() string {
+	return viper.GetString(shared.ConfigKeyOutputCustomFooter)
+}
+
+// TemplateCustomFileHeader returns custom file header template.
+// Default: ConfigCustomFileHeaderDefault (empty string).
+func TemplateCustomFileHeader() string {
+	return viper.GetString(shared.ConfigKeyOutputCustomFileHeader)
+}
+
+// TemplateCustomFileFooter returns custom file footer template.
+// Default: ConfigCustomFileFooterDefault (empty string).
+func TemplateCustomFileFooter() string {
+	return viper.GetString(shared.ConfigKeyOutputCustomFileFooter)
+}
+
+// TemplateVariables returns custom template variables.
+// Default: ConfigTemplateVariablesDefault (empty map).
+func TemplateVariables() map[string]string {
+	return viper.GetStringMapString(shared.ConfigKeyOutputVariables)
 }