refactor(playground): remove playgroundMaxTokens helper and update input handling

- Deleted the `playgroundMaxTokens` helper functions and their associated tests.
- Updated `loadConfig` and `usePlaygroundState` to handle `max_tokens` directly without sanitization.
- Simplified input handling in `usePlaygroundState` to directly set values without normalization.

web/src/components/playground/configStorage.js

@@ -21,7 +21,6 @@ import {
   STORAGE_KEYS,
   DEFAULT_CONFIG,
 } from '../../constants/playground.constants';
-import { sanitizePlaygroundInputs } from '../../helpers/playgroundMaxTokens';
 
 const MESSAGES_STORAGE_KEY = 'playground_messages';
 
@@ -66,12 +65,16 @@ export const loadConfig = () => {
     const savedConfig = localStorage.getItem(STORAGE_KEYS.CONFIG);
     if (savedConfig) {
       const parsedConfig = JSON.parse(savedConfig);
+      const parsedMaxTokens = parseInt(parsedConfig?.inputs?.max_tokens, 10);
 
       const mergedConfig = {
-        inputs: sanitizePlaygroundInputs({
+        inputs: {
           ...DEFAULT_CONFIG.inputs,
           ...parsedConfig.inputs,
-        }),
+          max_tokens: Number.isNaN(parsedMaxTokens)
+            ? parsedConfig?.inputs?.max_tokens
+            : parsedMaxTokens,
+        },
         parameterEnabled: {
           ...DEFAULT_CONFIG.parameterEnabled,
           ...parsedConfig.parameterEnabled,