refactor: remove SearXNG references and rename binary to kafka

- Rename cmd/searxng-go to cmd/kafka
- Remove all SearXNG references from source comments while keeping
  "SearXNG-compatible API" in user-facing docs
- Update binary paths in README, CLAUDE.md, and Dockerfile
- Update log message to "kafka starting"

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

cmd/searxng-go/main.go

@@ -1,112 +0,0 @@
-package main
-
-import (
-	"flag"
-	"fmt"
-	"io/fs"
-	"log"
-	"log/slog"
-	"net/http"
-	"os"
-
-	"github.com/metamorphosis-dev/kafka/internal/autocomplete"
-	"github.com/metamorphosis-dev/kafka/internal/cache"
-	"github.com/metamorphosis-dev/kafka/internal/config"
-	"github.com/metamorphosis-dev/kafka/internal/httpapi"
-	"github.com/metamorphosis-dev/kafka/internal/middleware"
-	"github.com/metamorphosis-dev/kafka/internal/search"
-	"github.com/metamorphosis-dev/kafka/internal/views"
-)
-
-func main() {
-	configPath := flag.String("config", "config.toml", "path to config.toml")
-	flag.Parse()
-
-	// Initialize structured logging.
-	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
-	slog.SetDefault(logger)
-
-	cfg, err := config.Load(*configPath)
-	if err != nil {
-		log.Fatalf("failed to load config: %v", err)
-	}
-
-	// Initialize Valkey cache.
-	searchCache := cache.New(cache.Config{
-		Address:    cfg.Cache.Address,
-		Password:   cfg.Cache.Password,
-		DB:         cfg.Cache.DB,
-		DefaultTTL: cfg.CacheTTL(),
-	}, logger)
-	defer searchCache.Close()
-
-	// Seed env vars from config so existing engine/factory/planner code
-	// picks them up without changes.
-	if len(cfg.Engines.LocalPorted) > 0 {
-		os.Setenv("LOCAL_PORTED_ENGINES", cfg.LocalPortedCSV())
-	}
-	if cfg.Engines.Brave.APIKey != "" {
-		os.Setenv("BRAVE_API_KEY", cfg.Engines.Brave.APIKey)
-	}
-	if cfg.Engines.Brave.AccessToken != "" {
-		os.Setenv("BRAVE_ACCESS_TOKEN", cfg.Engines.Brave.AccessToken)
-	}
-
-	svc := search.NewService(search.ServiceConfig{
-		UpstreamURL: cfg.Upstream.URL,
-		HTTPTimeout: cfg.HTTPTimeout(),
-		Cache:       searchCache,
-	})
-
-	acSvc := autocomplete.NewService(cfg.Upstream.URL, cfg.HTTPTimeout())
-
-	h := httpapi.NewHandler(svc, acSvc.Suggestions)
-
-	mux := http.NewServeMux()
-	mux.HandleFunc("/", h.Index)
-	mux.HandleFunc("/healthz", h.Healthz)
-	mux.HandleFunc("/search", h.Search)
-	mux.HandleFunc("/autocompleter", h.Autocompleter)
-	mux.HandleFunc("/opensearch.xml", h.OpenSearch(cfg.Server.BaseURL))
-
-	// Serve embedded static files (CSS, JS, images).
-	staticFS, err := views.StaticFS()
-	if err != nil {
-		log.Fatalf("failed to load static files: %v", err)
-	}
-	var subFS fs.FS = staticFS
-	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(subFS))))
-
-	// Apply middleware: global rate limit → burst rate limit → per-IP rate limit → CORS → handler.
-	var handler http.Handler = mux
-	handler = middleware.CORS(middleware.CORSConfig{
-		AllowedOrigins: cfg.CORS.AllowedOrigins,
-		AllowedMethods: cfg.CORS.AllowedMethods,
-		AllowedHeaders: cfg.CORS.AllowedHeaders,
-		ExposedHeaders: cfg.CORS.ExposedHeaders,
-		MaxAge:         cfg.CORS.MaxAge,
-	})(handler)
-	handler = middleware.RateLimit(middleware.RateLimitConfig{
-		Requests:        cfg.RateLimit.Requests,
-		Window:          cfg.RateLimitWindow(),
-		CleanupInterval: cfg.RateLimitCleanupInterval(),
-	}, logger)(handler)
-	handler = middleware.GlobalRateLimit(middleware.GlobalRateLimitConfig{
-		Requests: cfg.GlobalRateLimit.Requests,
-		Window:   cfg.GlobalRateLimitWindow(),
-	}, logger)(handler)
-	handler = middleware.BurstRateLimit(middleware.BurstRateLimitConfig{
-		Burst:           cfg.BurstRateLimit.Burst,
-		BurstWindow:     cfg.BurstWindow(),
-		Sustained:       cfg.BurstRateLimit.Sustained,
-		SustainedWindow: cfg.SustainedWindow(),
-	}, logger)(handler)
-
-	addr := fmt.Sprintf(":%d", cfg.Server.Port)
-	logger.Info("searxng-go starting",
-		"addr", addr,
-		"cache", searchCache.Enabled(),
-		"rate_limit", cfg.RateLimit.Requests > 0,
-	)
-	log.Fatal(http.ListenAndServe(addr, handler))
-}