feat: add advanced architecture, documentation, and coverage improvements (#65)

* fix(style): resolve PHPCS line-length warnings in source files

* fix(style): resolve PHPCS line-length warnings in test files

* feat(audit): add structured audit logging with ErrorContext and AuditContext

- ErrorContext: standardized error information with sensitive data sanitization
- AuditContext: structured context for audit entries with operation types
- StructuredAuditLogger: enhanced audit logger wrapper with timing support

* feat(recovery): add recovery mechanism for failed masking operations

- FailureMode enum: FAIL_OPEN, FAIL_CLOSED, FAIL_SAFE modes
- RecoveryStrategy interface and RecoveryResult value object
- RetryStrategy: exponential backoff with configurable attempts
- FallbackMaskStrategy: type-aware fallback values

* feat(strategies): add CallbackMaskingStrategy for custom masking logic

- Wraps custom callbacks as MaskingStrategy implementations
- Factory methods: constant(), hash(), partial() for common use cases
- Supports exact match and prefix match for field paths

* docs: add framework integration guides and examples

- symfony-integration.md: Symfony service configuration and Monolog setup
- psr3-decorator.md: PSR-3 logger decorator pattern implementation
- framework-examples.md: CakePHP, CodeIgniter 4, Laminas, Yii2, PSR-15
- docker-development.md: Docker development environment guide

* chore(docker): add Docker development environment

- Dockerfile: PHP 8.2-cli-alpine with Xdebug for coverage
- docker-compose.yml: development services with volume mounts

* feat(demo): add interactive GDPR pattern tester playground

- PatternTester.php: pattern testing utility with strategy support
- index.php: web API endpoint with JSON response handling
- playground.html: interactive web interface for testing patterns

* docs(todo): update with completed medium priority items

- Mark all PHPCS warnings as fixed (81 → 0)
- Document new Audit and Recovery features
- Update test count to 1,068 tests with 2,953 assertions
- Move remaining items to low priority

* feat: add advanced architecture, documentation, and coverage improvements

- Add architecture improvements:
  - ArrayAccessorInterface and DotArrayAccessor for decoupled array access
  - MaskingOrchestrator for single-responsibility masking coordination
  - GdprProcessorBuilder for fluent configuration
  - MaskingPluginInterface and AbstractMaskingPlugin for plugin architecture
  - PluginAwareProcessor for plugin hook execution
  - AuditLoggerFactory for instance-based audit logger creation

- Add advanced features:
  - SerializedDataProcessor for handling print_r/var_export/serialize output
  - KAnonymizer with GeneralizationStrategy for GDPR k-anonymity
  - RetentionPolicy for configurable data retention periods
  - StreamingProcessor for memory-efficient large log processing

- Add comprehensive documentation:
  - docs/performance-tuning.md - benchmarking, optimization, caching
  - docs/troubleshooting.md - common issues and solutions
  - docs/logging-integrations.md - ELK, Graylog, Datadog, etc.
  - docs/plugin-development.md - complete plugin development guide

- Improve test coverage (84.41% → 85.07%):
  - ConditionalRuleFactoryInstanceTest (100% coverage)
  - GdprProcessorBuilderEdgeCasesTest (100% coverage)
  - StrategyEdgeCasesTest for ReDoS detection and type parsing
  - 78 new tests, 119 new assertions

- Update TODO.md with current statistics:
  - 141 PHP files, 1,346 tests, 85.07% line coverage

* chore: tests, update actions, sonarcloud issues

* chore: rector

* fix: more sonarcloud fixes

* chore: more fixes

* refactor: copilot review fix

* chore: rector

src/Contracts/ArrayAccessorInterface.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Ivuorinen\MonologGdprFilter\Contracts;
+
+/**
+ * Interface for dot-notation array access.
+ *
+ * This abstraction allows swapping the underlying implementation
+ * (e.g., Adbar\Dot) without modifying consuming code.
+ *
+ * @api
+ */
+interface ArrayAccessorInterface
+{
+    /**
+     * Check if a key exists using dot notation.
+     *
+     * @param string $path Dot-notation path (e.g., "user.email")
+     */
+    public function has(string $path): bool;
+
+    /**
+     * Get a value using dot notation.
+     *
+     * @param string $path Dot-notation path (e.g., "user.email")
+     * @param mixed $default Default value if path doesn't exist
+     * @return mixed The value at the path or default
+     */
+    public function get(string $path, mixed $default = null): mixed;
+
+    /**
+     * Set a value using dot notation.
+     *
+     * @param string $path Dot-notation path (e.g., "user.email")
+     * @param mixed $value Value to set
+     */
+    public function set(string $path, mixed $value): void;
+
+    /**
+     * Delete a value using dot notation.
+     *
+     * @param string $path Dot-notation path (e.g., "user.email")
+     */
+    public function delete(string $path): void;
+
+    /**
+     * Get all data as an array.
+     *
+     * @return array<string, mixed> The complete data array
+     */
+    public function all(): array;
+}

src/Contracts/MaskingPluginInterface.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Ivuorinen\MonologGdprFilter\Contracts;
+
+/**
+ * Interface for masking plugins that can extend GdprProcessor functionality.
+ *
+ * Plugins can hook into the masking process at various points to add
+ * custom masking logic, transformations, or integrations.
+ *
+ * @api
+ */
+interface MaskingPluginInterface
+{
+    /**
+     * Get the unique plugin identifier.
+     */
+    public function getName(): string;
+
+    /**
+     * Process context data before standard masking is applied.
+     *
+     * @param array<string,mixed> $context The context data
+     * @return array<string,mixed> The modified context data
+     */
+    public function preProcessContext(array $context): array;
+
+    /**
+     * Process context data after standard masking is applied.
+     *
+     * @param array<string,mixed> $context The masked context data
+     * @return array<string,mixed> The modified context data
+     */
+    public function postProcessContext(array $context): array;
+
+    /**
+     * Process message before standard masking is applied.
+     *
+     * @param string $message The original message
+     * @return string The modified message
+     */
+    public function preProcessMessage(string $message): string;
+
+    /**
+     * Process message after standard masking is applied.
+     *
+     * @param string $message The masked message
+     * @return string The modified message
+     */
+    public function postProcessMessage(string $message): string;
+
+    /**
+     * Get additional patterns to add to the processor.
+     *
+     * @return array<string,string> Regex pattern => replacement
+     */
+    public function getPatterns(): array;
+
+    /**
+     * Get additional field paths to mask.
+     *
+     * @return array<string,\Ivuorinen\MonologGdprFilter\FieldMaskConfig|string>
+     */
+    public function getFieldPaths(): array;
+
+    /**
+     * Get the plugin's priority (lower = earlier execution).
+     */
+    public function getPriority(): int;
+}