feat: add AVE Cloud Skills integration for conversational agent

- Add subprocess-based AVE Cloud Skills CLI integration for token data
- Add new tools: search_tokens, get_token, get_price, get_risk, get_trending
- Add get_trending tool for trending tokens on BSC
- Replace direct API calls with CLI subprocess calls

Bug fixes:
- Fix repo_root path calculation (5 → 6 dirname() calls)
- Handle API response where data is a list instead of dict
- Add defensive type checking for all API responses
- Handle string values in market_cap and volume formatting
- Handle None values before calling len()
- Handle nested token data structure (data.token) and alternative field names
- Handle integer/bool types for honeypot check (1/0 vs true/false)
- Handle -1 as unknown for honeypot status
- Show raw API response for debugging when data is missing

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "ave-cloud-skill"]
+	path = ave-cloud-skill
+	url = https://github.com/AveCloud/ave-cloud-skill.git

src/backend/app/ave

@@ -0,0 +1 @@
+../../ave-cloud-skill/scripts/ave