Merge remote main and fix MITM proxy: keep-alive, cert expiry, compre…

…ssed response handling

Refactor MITM proxy: improve header handling, server behavior, and co…

…nnection management

- Add `IdleTimeout` to HTTP server for better connection lifecycle management.
- Abstract hop-by-hop header removal into `removeHopByHopHeaders` for cleaner code.
- Refine `singleConnListener` with better synchronization and blocking logic to prevent premature shutdown.
- Modify `Accept-Encoding` handling to support transparent decompression by Go's HTTP transport.

Add `sanitize_keys` and `skip_keys` support to sanitizer configuration

- Introduce `KeyConfig` to manage JSON field sanitization and exclusion rules.
- Update sanitizer to use default or custom key configurations for masking and skipping fields.
- Replace `interestingKeys` with configurable `sanitize_keys` and `skip_keys`.
- Add tests to validate new key configuration behavior and edge cases for masking logic.
- Update README with documentation for `sanitize_keys` and `skip_keys` parameters.

Remove `test-ner-debug` tool and its dependencies from the project

Remove unused functions and imports from ONNX NER detector and tokenizer

Refactor stats rendering and export logic

Enhance process management and stats server handling

- Add fallback to find and terminate `velard` process by name if PID file is missing
- Implement reusable `killProcess` and `findVelardProcess` helpers
- Improve `daemonCommand` to locate `velard` binary more robustly
- Refactor stats server to use SO_REUSEADDR listener for better socket reuse

Refactor stats rendering and export logic

Add comprehensive secret detectors and sanitizer integration (#23)

Add optional response restoration config

- Add `restore_responses` field to Sanitizer config (default: true)
- Add `WithRestoreResponses()` method to SanitizingInspector
- Skip restoration if disabled in config
- Update README with new config option
- All tests passing

This allows users to disable automatic restoration of masked values
in responses if they want placeholders to remain in the output.

Example config:
```yaml
sanitizer:
  enabled: true
  restore_responses: false  # Keep placeholders in responses
```