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/model/model.go

@@ -2,6 +2,8 @@
 // classifier, pipeline and store.
 package model
 
+import "time"
+
 // Provider identifies a cloud/database/storage provider.
 type Provider uint8
 
@@ -205,6 +207,17 @@ type Match struct {
 	Resource         string
 }
 
+// Entry is one indexed item of a readable resource (object key, container,
+// prefix, database index, root key). It is metadata only — never the content.
+type Entry struct {
+	Kind        string // object | prefix | container | key | index
+	Name        string
+	Size        int64
+	Updated     time.Time
+	ContentType string
+	ETag        string
+}
+
 // Candidate is a provider resource discovered directly or through DNS.
 type Candidate struct {
 	Hostname         string // hostname that matched (provider hostname)