Organize shared code across web, mobile, and SDK UI projects

Centralized common code into shared/ folder to eliminate duplication and
improve maintainability across all three frontend projects (web, mobile,
pezkuwi-sdk-ui).

Changes:
- Added token types and constants to shared/types/tokens.ts
  - TokenInfo, PoolInfo, SwapQuote, and other DEX types
  - KNOWN_TOKENS with HEZ, PEZ, wUSDT definitions
  - Token logos (🟡🟣💵)

- Added Kurdistan color palette to shared/constants/
  - Kesk, Sor, Zer, Spî, Reş color definitions

- Added TOKEN_DISPLAY_SYMBOLS mapping (USDT vs wUSDT)

- Updated blockchain configuration in shared/blockchain/polkadot.ts
  - Added beta testnet endpoint (wss://beta-rpc.pezkuwi.art)
  - Defined DEFAULT_ENDPOINT constant

- Moved i18n to shared/i18n/
  - Centralized translation files for 6 languages (EN, TR, KMR, CKB, AR, FA)
  - Added LANGUAGES configuration with RTL support
  - Created isRTL() helper function

- Updated web and mobile to import from shared
  - web/src/types/dex.ts now re-exports from shared
  - web/src/contexts/PolkadotContext.tsx uses DEFAULT_ENDPOINT
  - mobile/src/i18n/index.ts uses shared translations
  - mobile/src/contexts/PolkadotContext.tsx uses DEFAULT_ENDPOINT

- Updated shared/README.md with comprehensive documentation

This architecture reduces code duplication and ensures consistency across
all frontend projects.

shared/types/index.ts

@@ -8,4 +8,7 @@
 // Export blockchain-related types here
 export * from './blockchain';
 
+// Export token-related types
+export * from './tokens';
+
 // Add more type exports as needed