## Problem
GetCurrentKlines had two critical bugs causing price data to become stale:
1. Incorrect return logic: returned error even when data fetch succeeded
2. Race condition: returned slice reference instead of deep copy, causing concurrent data corruption
## Impact
- BTC price stuck at 106xxx while actual market price was 107xxx+
- LLM calculated take-profit based on stale prices → orders failed validation
- Statistics showed incorrect P&L (0.00%) due to corrupted historical data
- Alt-coins filtered out due to failed market data fetch
## Solution
1. Fixed return logic: only return error when actual failure occurs
2. Return deep copy instead of reference to prevent race conditions
3. Downgrade subscription errors to warnings (non-blocking)
## Test Results
✅ Price updates in real-time
✅ Take-profit orders execute successfully
✅ P&L calculations accurate
✅ Alt-coins now tradeable
Related: Price feed mechanism, concurrent data access
Fixed critical bug where 4h kline data was incorrectly stored with
3m kline data, causing data mismatch.
Changes:
- Changed `m.klineDataMap4h.Store(s, klines)` to `klines4h`
- Updated log message to use `len(klines4h)` instead of `len(klines)`
This bug would cause 4h kline queries to return 3m data, leading to
incorrect technical indicator calculations.
Fixes: #260
Related: #176
