Bucketeer UI (dark mode, pagination, virtual scroll), readable+indexed resources, LLM-friendly logs

Logging:
- structured slog with LOG_FORMAT=json|text and a stable key vocabulary
- periodic stats record with queue depths, db pool, goroutines, memory, dns/probe
- no per-certificate logging (hot path is counters only)

UI (Bucketeer branding, DESIGN.md):
- light+dark themes (OS default, persisted header toggle, no first-paint flash)
- official mascot: lossless WebP light/dark logos + favicon, embedded and served
  with cache headers (1.2MB source PNGs -> ~27/22KB webp)
- Assets/Contents views, pagination (offset) and native virtual scrolling
  (content-visibility) so large result sets do not blow up the DOM
- search with debounce/abort + URL state, exposure chips, sort, summary counts

Readability + indexing:
- internal/index listers for S3-compatible, GCS, Azure, Firebase, OpenSearch
  (metadata only: keys/sizes/dates; never object contents)
- asset_entries table + store write/search; readable resources are indexed and
  searchable in the UI
- deep, unauthenticated, read-only DB probes (PROBE_DEEP): Redis PING,
  PostgreSQL StartupMessage, MongoDB OP_MSG listDatabases; OpenSearch/Neptune
  HTTP reads
- Azure account-level listing fixed: 403 is reported reachable, not
  auth_required, since anonymous access is per-container

DNS:
- curated reliable resolvers by default; DNS_SERVERS=fresh adds the compiled-in
  Fresh-Resolvers snapshot with a bounded startup sample (warming all 6.7k at
  once broke the container resolver)
- random healthy selection + failover + per-server cooldown

Other: prober Close fixes a shutdown hang; config/README updated.

internal/config/config.go

@@ -31,15 +31,19 @@ type Config struct {
 	DBBatchSize     int
 	DBFlushInterval time.Duration
 
-	ActiveProbing  bool
-	ProbeWorkers   int
-	ProbeTimeout   time.Duration
-	ProbeQueueSize int
+	ActiveProbing   bool
+	ProbeWorkers    int
+	ProbeTimeout    time.Duration
+	ProbeQueueSize  int
+	ProbeDeep       bool
+	IndexEnabled    bool
+	IndexMaxObjects int
 
 	MetricsAddr   string
 	UIUser        string
 	UIPass        string
 	LogLevel      string
+	LogFormat     string
 	StatsInterval time.Duration
 
 	LogListSource   string
@@ -51,15 +55,11 @@ type Config struct {
 // DefaultLogListSource is the public CT log list used by certspotter.
 const DefaultLogListSource = "https://www.gstatic.com/ct/log_list/v3/log_list.json"
 
-// DefaultDNSServers are load-balanced across. Set DNS_SERVERS=system to use the
-// host resolver instead, or provide your own comma-separated list.
-var DefaultDNSServers = []string{"1.1.1.1:53", "8.8.8.8:53", "1.0.0.1:53"}
-
 func Load() (*Config, error) {
 	c := &Config{
 		DatabaseURL:      os.Getenv("DATABASE_URL"),
 		DBMaxConns:       envInt("DB_MAX_CONNS", 8),
-		DNSServers:       envList("DNS_SERVERS", DefaultDNSServers),
+		DNSServers:       envList("DNS_SERVERS", nil),
 		DNSWorkers:       envInt("DNS_WORKERS", 16),
 		DNSTimeout:       envDuration("DNS_TIMEOUT", 5*time.Second),
 		DNSCacheSize:     envInt("DNS_CACHE_SIZE", 1<<18),
@@ -76,10 +76,14 @@ func Load() (*Config, error) {
 		ProbeWorkers:     envInt("PROBE_WORKERS", 8),
 		ProbeTimeout:     envDuration("PROBE_TIMEOUT", 5*time.Second),
 		ProbeQueueSize:   envInt("PROBE_QUEUE_SIZE", 1<<16),
+		ProbeDeep:        envBool("PROBE_DEEP", true),
+		IndexEnabled:     envBool("INDEX_ENABLED", true),
+		IndexMaxObjects:  envInt("INDEX_MAX_OBJECTS", 1000),
 		MetricsAddr:      envString("METRICS_ADDR", ":9090"),
 		UIUser:           envString("UI_USER", ""),
 		UIPass:           envString("UI_PASS", ""),
 		LogLevel:         envString("LOG_LEVEL", "info"),
+		LogFormat:        envString("LOG_FORMAT", "text"),
 		StatsInterval:    envDuration("STATS_INTERVAL", 60*time.Second),
 		LogListSource:    envString("LOG_LIST_SOURCE", DefaultLogListSource),
 		StartAtEnd:       envBool("START_AT_END", false),
@@ -113,6 +117,11 @@ func (c *Config) validate() error {
 	default:
 		return fmt.Errorf("LOG_LEVEL must be one of debug, info, warn, error")
 	}
+	switch c.LogFormat {
+	case "text", "json":
+	default:
+		return fmt.Errorf("LOG_FORMAT must be text or json")
+	}
 	return nil
 }