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/cmd/api-gateway/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bufio"
+	"context"
 	"fmt"
 	"io"
 	"log"
@@ -15,6 +16,7 @@ import (
 	"github.com/gofiber/fiber/v2/middleware/logger"
 	"github.com/gooseek/backend/pkg/config"
 	"github.com/gooseek/backend/pkg/middleware"
+	"github.com/redis/go-redis/v9"
 )
 
 var svcURLs map[string]string
@@ -25,6 +27,19 @@ func main() {
 		log.Fatal("Failed to load config:", err)
 	}
 
+	opt, err := redis.ParseURL(cfg.RedisURL)
+	if err != nil {
+		log.Printf("Warning: failed to parse Redis URL, rate limiting will be disabled: %v", err)
+	}
+	var redisClient *redis.Client
+	if opt != nil {
+		redisClient = redis.NewClient(opt)
+		if _, err := redisClient.Ping(context.Background()).Result(); err != nil {
+			log.Printf("Warning: Redis not available, rate limiting will be disabled: %v", err)
+			redisClient = nil
+		}
+	}
+
 	svcURLs = map[string]string{
 		"auth":     cfg.AuthSvcURL,
 		"chat":     cfg.ChatSvcURL,
@@ -62,14 +77,17 @@ func main() {
 		AllowGuest: true,
 	}))
 
-	app.Use(middleware.TieredRateLimit(middleware.TieredRateLimitConfig{
-		Tiers: map[string]middleware.TierConfig{
-			"free":     {Max: 60, Window: time.Minute},
-			"pro":      {Max: 300, Window: time.Minute},
-			"business": {Max: 1000, Window: time.Minute},
-		},
-		DefaultTier: "free",
-	}))
+	if redisClient != nil {
+		app.Use(middleware.TieredRateLimit(middleware.TieredRateLimitConfig{
+			RedisClient: redisClient,
+			Tiers: map[string]middleware.TierConfig{
+				"free":     {Max: 60, Window: time.Minute},
+				"pro":      {Max: 300, Window: time.Minute},
+				"business": {Max: 1000, Window: time.Minute},
+			},
+			DefaultTier: "free",
+		}))
+	}
 
 	app.Get("/health", func(c *fiber.Ctx) error {
 		return c.JSON(fiber.Map{"status": "ok"})