feat: implement buy-low-sell-high market maker (no splitPosition)

New market maker strategy that places limit BUY on UP+DOWN at low price
(default 2c), then sells at target price (default 3c) when filled.

Key features:
- Concurrent limit BUY on both sides (multi-thread style via Promise.all)
- Immediate partial sell placement on partial fill detection
- Cancel opposite side when one fills completely
- WebSocket orderbook client for real-time simulation visualization
- Both TUI (maker.js) and bot (maker-bot.js) entry points

Files:
- services/makerDetector.js: market detection (reuses slug pattern)
- services/makerExecutor.js: core buy-low-sell-high strategy
- services/makerWs.js: WebSocket orderbook for live data
- maker.js: TUI version with blessed dashboard
- maker-bot.js: PM2/VPS plain-text version

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -21,7 +21,13 @@
     "sniper-dev": "DRY_RUN=true nodemon --ignore 'data/*.json' src/sniper.js",
     "sniper-tui": "DRY_RUN=false node src/sniper-tui.js",
     "sniper-tui-sim": "DRY_RUN=true node src/sniper-tui.js",
-    "sniper-tui-dev": "DRY_RUN=true nodemon --ignore 'data/*.json' src/sniper-tui.js"
+    "sniper-tui-dev": "DRY_RUN=true nodemon --ignore 'data/*.json' src/sniper-tui.js",
+    "maker": "DRY_RUN=false node src/maker.js",
+    "maker-sim": "DRY_RUN=true node src/maker.js",
+    "maker-dev": "DRY_RUN=true nodemon --ignore 'data/*.json' src/maker.js",
+    "maker-bot": "node src/maker-bot.js",
+    "maker-bot-sim": "DRY_RUN=true node src/maker-bot.js",
+    "maker-bot-dev": "DRY_RUN=true nodemon --ignore 'data/*.json' src/maker-bot.js"
   },
   "keywords": [
     "polymarket",