Add unit tests for hyperliquid skill functionality

- Implement tests for normalizing perpetual markets and DEXs.
- Validate JSON output for main commands including markets, candles, and review.
- Ensure environment variable resolution and dotenv file reading are covered.
- Test export functionality for market data with expected output structure.

.env.example

@@ -143,6 +143,18 @@
 # Also requires ~/.honcho/config.json with enabled=true (see README).
 # HONCHO_API_KEY=
 
+# =============================================================================
+# HYPERLIQUID OPTIONAL SKILL
+# =============================================================================
+# Optional defaults for the Hyperliquid skill in optional-skills/blockchain/hyperliquid
+#
+# Hyperliquid API base URL override
+# Default: https://api.hyperliquid.xyz
+# HYPERLIQUID_API_URL=https://api.hyperliquid-testnet.xyz
+#
+# Default address for account-level commands like state, fills, orders, and review
+# HYPERLIQUID_USER_ADDRESS=0x0000000000000000000000000000000000000000
+
 # =============================================================================
 # TERMINAL TOOL CONFIGURATION
 # =============================================================================