add: 30d/90d/180d/365d forward returns in all backtest views

- Bracket table now shows Avg 30d, 90d, 180d, and 1yr columns
- Signal events show all 4 timeframes
- Current context shows all 4 average returns
- Comparable examples show all available timeframes
- Updated backtest screenshot

config/llm_settings.json

@@ -1,6 +1,6 @@
 {
-  "provider": "ollama",
-  "model": "qwen3.5:27b",
+  "provider": "openrouter",
+  "model": "minimax/minimax-m2.5",
   "providers": {
     "ollama": {
       "base_url": "http://100.100.242.21:11434"
@@ -15,7 +15,7 @@
       "api_key": ""
     },
     "openrouter": {
-      "api_key": ""
+      "api_key": "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"
     }
   }
-}
+}