Clean up unused files, organize structure, update docs

- Delete obsolete files: data_fetcher_old.py, market_old.py, base_strategy.py (root),
  strategy_sma_cross.py, and old architecture remnants (address_monitor.py,
  position_monitor.py, trade_log.py, wallet_data.py, whale_tracker.py)
- Delete zero-byte Docker artifacts and runtime files (clp_hedger.log,
  clp_hedger/hedge_status.json)
- Move one-off utility scripts to scripts/ directory
- Move example/template files to .temp/ directory
- Update .gitignore: add entries for clp_hedger.log, clp_hedger/hedge_status.json,
  Docker layer hash files, Using, Running, and backups/
- Update .dockerignore: add clp_hedger.log, clp_hedger/hedge_status.json, backups/
- Create example config files: _data/strategies.json.example,
  _data/backtesting_conf.json.example, _data/coin_precision.json.example
- Update GEMINI.md: remove outdated session summaries and duplicate review section
- Update review.md: add cleanup status section, update remaining recommendations
- Update MIGRATION_PLAN.md: mark completed phases, update file references
- Update DOCKER_MIGRATION_GUIDE.md: update import_csv.py path reference

_data/backtesting_conf.json.example

@@ -0,0 +1,18 @@
+{
+    "sma_cross_eth_5m": {
+        "strategy_name": "sma_cross_1",
+        "script": "strategies.ma_cross_strategy.MaCrossStrategy",
+        "optimization_params": {
+            "fast": {
+                "start": 5,
+                "end": 150,
+                "step": 1
+            },
+            "slow": {
+                "start": 0,
+                "end": 0,
+                "step": 1
+            }
+        }
+    }
+}