feat: spaces redesign, model selector, auth fixes

Spaces:
- Perplexity-like UI with collaboration features
- Space detail page with threads/members tabs
- Invite members via email, role management
- New space creation with icon/color picker

Model selector:
- Added Ollama client for free Auto model
- GooSeek 1.0 via Timeweb (tariff-based)
- Frontend model dropdown in ChatInput

Auth & Infrastructure:
- Fixed auth-svc missing from Dockerfile.all
- Removed duplicate ratelimit_tiered.go (conflict)
- Added Redis to api-gateway for rate limiting
- Fixed Next.js proxy for local development

UI improvements:
- Redesigned login button in sidebar (gradient)
- Settings page with tabs (account/billing/prefs)
- Auth pages visual refresh

Made-with: Cursor

backend/internal/llm/client.go

@@ -79,6 +79,11 @@ type ProviderConfig struct {
 
 func NewClient(cfg ProviderConfig) (Client, error) {
 	switch cfg.ProviderID {
+	case "ollama":
+		return NewOllamaClient(OllamaConfig{
+			BaseURL:  cfg.BaseURL,
+			ModelKey: cfg.ModelKey,
+		})
 	case "timeweb":
 		return NewTimewebClient(TimewebConfig{
 			BaseURL:       cfg.BaseURL,