feat: typed script parameters with validation and icon-grid selector

- Add ScriptParameterConfig model (string, integer, float, boolean, select types)
- Server-side validation at both define-time and execute-time
- Parameters passed as SCRIPT_PARAM_* environment variables
- Web UI parameter editor in script create/edit dialog (add/remove/reorder)
- Icon-grid selector component (ported from wled-screen-controller)
- Replace audio device dropdown with icon-grid selector
- Replace callback event dropdown with icon-grid selector
- Localization for parameter UI (en, ru)

media_server/static/js/app.js

@@ -40,6 +40,7 @@ import {
     showAddScriptDialog, showEditScriptDialog, closeScriptDialog, saveScript,
     deleteScriptConfirm, executeScriptDebug, executeCallbackDebug,
     closeExecutionDialog, scriptFormDirty, setScriptFormDirty,
+    addParameterRow, closeScriptParamsDialog, submitScriptWithParams,
 } from './scripts.js';
 
 import {
@@ -106,6 +107,7 @@ Object.assign(window, {
     showAddScriptDialog, showEditScriptDialog, closeScriptDialog, saveScript,
     deleteScriptConfirm, executeScriptDebug, executeCallbackDebug,
     closeExecutionDialog,
+    addParameterRow, closeScriptParamsDialog, submitScriptWithParams,
     // Callbacks
     showAddCallbackDialog, showEditCallbackDialog, closeCallbackDialog,
     saveCallback, deleteCallbackConfirm,