Add Blossom bandwidth limiting and tune rate limiters (v0.49.0)

- Add token-bucket bandwidth rate limiting for Blossom uploads
  - ORLY_BLOSSOM_RATE_LIMIT enables limiting (default: false)
  - ORLY_BLOSSOM_DAILY_LIMIT_MB sets daily limit (default: 10MB)
  - ORLY_BLOSSOM_BURST_LIMIT_MB sets burst cap (default: 50MB)
  - Followed users, admins, owners are exempt (unlimited)
- Change emergency mode throttling from exponential to linear scaling
  - Old: 16x multiplier at emergency threshold entry
  - New: 1x at threshold, +1x per 20% excess pressure
- Reduce follows ACL throttle increment from 200ms to 25ms per event
- Update dependencies

Files modified:
- app/blossom.go: Pass rate limit config to blossom server
- app/config/config.go: Add Blossom rate limit config options
- pkg/blossom/ratelimit.go: New bandwidth limiter implementation
- pkg/blossom/server.go: Add rate limiter integration
- pkg/blossom/handlers.go: Check rate limits on upload/mirror/media
- pkg/ratelimit/limiter.go: Linear emergency throttling
- pkg/acl/follows.go: Reduce default throttle increment

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pkg/event/routing/ephemeral.go

@@ -3,6 +3,7 @@ package routing
 import (
 	"git.mleku.dev/mleku/nostr/encoders/event"
 	"git.mleku.dev/mleku/nostr/encoders/kind"
+	"lol.mleku.dev/log"
 )
 
 // Publisher abstracts event delivery to subscribers.
@@ -22,6 +23,7 @@ func IsEphemeral(k uint16) bool {
 // - Are immediately delivered to subscribers
 func MakeEphemeralHandler(publisher Publisher) Handler {
 	return func(ev *event.E, authedPubkey []byte) Result {
+		log.I.F("ephemeral handler received event kind %d, id %0x", ev.Kind, ev.ID[:8])
 		// Clone and deliver immediately without persistence
 		cloned := ev.Clone()
 		go publisher.Deliver(cloned)