fix: prevent DeepSeek token overflow with product-level limits (#1431)

* feat: enforce strategy limits to prevent token overflow

* fix: tune token limits after real-world testing

- Relax kline max 20→30, timeframes 3→4 (tested ~41K tokens, safe under 131K)
- Restore ranking limits to original [5,10,15,20] options (only ~1.5K token impact)
- Add static coins limit (max 3) with toast notification
- Add timeframe limit toast when exceeding 4
- Log SSE token usage (prompt/completion/total) from API response
- Fix nil logger crash in claw402 data client (engine.go)

* feat: add token estimation functionality for strategy configurations

* feat: add discard changes button in Strategy Studio for unsaved modifications

* feat: retain selected strategy after saving in Strategy Studio

* feat: enhance strategy display in Strategy Studio with improved layout and sorting of token limits

* refactor: improve layout and styling of stats display in CompetitionPage

* refactor: replace select elements with NofxSelect component for improved consistency in strategy configuration forms

* style: update NofxSelect component to use smaller text size for improved readability

* feat: implement token overflow handling in strategy updates and UI

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Co-authored-by: Dean <afei.wuhao@gmail.com>

api/server.go

@@ -110,6 +110,7 @@ func (s *Server) setupRoutes() {
 
 		// Public strategy market (no authentication required)
 		s.route(api, "GET", "/strategies/public", "Public strategy market", s.handlePublicStrategies)
+		s.route(api, "POST", "/strategies/estimate-tokens", "Estimate token usage for a strategy config", s.handleEstimateTokens)
 
 		// Authentication related routes (no authentication required)
 		s.route(api, "POST", "/register", "Register new user", s.handleRegister)