Add option to use a cabinet impulse response in plugin

[jedlamartin]

Feature Request:

Add functionality to allow users to select between the following cabinet impulse response (IR) options when using the plugin:

• Use the basic (built-in) cabinet impulse response
• Import and use a custom cabinet impulse response of the user's choice
• Use the plugin with no cabinet impulse response at all

Requirements:

• The UI should provide an option for the user to select one of the above three settings
• If the user chooses to import a custom IR, provide a clear and simple import workflow
• Store the imported IR for the current project/session and give feedback if import is not successful
• If "no IR" is selected, the plugin output should bypass any cabinet simulation

Benefits:

• Increases plugin flexibility for different user preferences and workflows
• Supports more advanced use-cases with custom IRs
• Allows purist users or re-amping setups to use plugin output without any IR coloration

Acceptance Criteria:

• A clear selector or toggle is present in the UI for IR mode
• Custom IR import works for standard IR file formats (WAV, AIFF, etc.)
• Help text/tooltips are provided for each mode
• The feature is documented in the user guide/readme

[jedlamartin]

Implemented in v1.1.0 via ReSinc integration and custom/bypass IR options.