Memby v0.1.53: Android TV client plus gateway

Android TV client for Emby (Kotlin, Compose for TV) and the Memby gateway
(Go, Postgres, Redis) that fronts it.

Client:
- Setup, profiles, home rows, Media3 playback, system screensaver (Dream)
- Backend chosen at build time: gateway when memby.gatewayUrl is set,
  otherwise direct to Emby. Both paths stay working.
- Server-composed home rows, rendered verbatim so new row types ship
  without an app release
- Full-screen animated maintenance state, row engagement telemetry

Gateway:
- One request per TV screen; auth, caching, search and row shaping
- Library import from Emby into Postgres (manual, then hourly incremental)
- Recommendations from viewing history (recency-weighted genre affinity)
- Admin page for imports, an offline switch, and per-row analytics
- Video always direct-plays from Emby; only metadata passes through

Identity is com.ponzischeme89.memby throughout, replacing
com.mattcohen.embyclientsname. A changed applicationId installs as a new
app: TVs need a fresh sign-in and the old package uninstalled.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

server/internal/api/health.go

@@ -0,0 +1,49 @@
+package api
+
+import (
+	"context"
+	"encoding/hex"
+	"net/http"
+	"time"
+)
+
+func hexHash(hash []byte) string { return hex.EncodeToString(hash) }
+
+// handleHealth is liveness: the process is up. It touches no dependency, so an
+// orchestrator does not restart the container just because Emby is down.
+func (s *Server) handleHealth(w http.ResponseWriter, _ *http.Request) {
+	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
+}
+
+// handleReady is readiness: everything this service needs is reachable.
+func (s *Server) handleReady(w http.ResponseWriter, r *http.Request) {
+	ctx, cancel := context.WithTimeout(r.Context(), 3*time.Second)
+	defer cancel()
+
+	checks := map[string]string{}
+	status := http.StatusOK
+
+	if err := s.store.Ping(ctx); err != nil {
+		checks["postgres"] = err.Error()
+		status = http.StatusServiceUnavailable
+	} else {
+		checks["postgres"] = "ok"
+	}
+
+	if err := s.cache.Ping(ctx); err != nil {
+		checks["redis"] = err.Error()
+		status = http.StatusServiceUnavailable
+	} else {
+		checks["redis"] = "ok"
+	}
+
+	// Emby being unreachable is reported but does not fail readiness: cached responses
+	// are still worth serving, and flapping the container would not bring Emby back.
+	if err := s.emby.Ping(ctx); err != nil {
+		checks["emby"] = err.Error()
+	} else {
+		checks["emby"] = "ok"
+	}
+
+	writeJSON(w, status, checks)
+}