Add multi-language support for UI

- Add 30 new locale files (ar, bn, cs, da, de, el, es, fi, fr, he, hi, hu, id, it, ja, ko, nl, no, pl, pt-BR, pt-PT, ro, ru, sv, th, tl, tr, uk, ur, zh-TW)
- Update i18n config to register new languages
- Update LanguageSwitcher component to support expanded language list
- Update localDb and pricing constants for i18n compatibility

Made-with: Cursor

src/shared/constants/pricing.js

@@ -751,9 +751,38 @@ export const DEFAULT_PRICING = {
       reasoning: 3.00,
       cache_creation: 0.50
     }
+  },
+
+  // DeepSeek (official API pricing: https://api-docs.deepseek.com/quick_start/pricing)
+  deepseek: {
+    "deepseek-chat": {
+      input: 0.28,
+      output: 0.42,
+      cached: 0.028,
+      reasoning: 0.42,
+      cache_creation: 0.28
+    },
+    "deepseek-reasoner": {
+      input: 0.28,
+      output: 0.42,
+      cached: 0.028,
+      reasoning: 0.42,
+      cache_creation: 0.28
+    }
   }
 };
 
+/**
+ * Provider-agnostic fallback pricing, keyed by model base name.
+ * Used when provider-specific lookup fails (e.g. openrouter, cu, fireworks use prefixed model IDs).
+ * Strip prefix before lookup: "deepseek/deepseek-chat" → "deepseek-chat"
+ */
+export const MODEL_PRICING = {
+  // DeepSeek
+  "deepseek-chat":     { input: 0.28, output: 0.42, cached: 0.028, reasoning: 0.42, cache_creation: 0.28 },
+  "deepseek-reasoner": { input: 0.28, output: 0.42, cached: 0.028, reasoning: 0.42, cache_creation: 0.28 },
+};
+
 /**
  * Get pricing for a specific provider and model
  * @param {string} provider - Provider ID (e.g., "openai", "cc", "gc")