feat: expand companion platform, device controls, and memoir workflows

Add customer and operator login, BLE provisioning, device fleet controls, call memory, memoir generation, and refreshed family and maintenance portals. Include API contracts, migrations, firmware sources, tests, assets, and deployment documentation.

cmd/elder-agent/main.go

@@ -0,0 +1,47 @@
+// Backfill an existing elder using the same provisioner as POST /subjects.
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"os"
+
+	"data-terminal-cloud/internal/config"
+	"data-terminal-cloud/internal/database"
+	"data-terminal-cloud/internal/elderagent"
+)
+
+func main() {
+	subject := flag.String("subject", "", "existing elder public ID")
+	flag.Parse()
+	if *subject == "" {
+		fmt.Fprintln(os.Stderr, "--subject is required")
+		os.Exit(2)
+	}
+	cfg, err := config.Load("api")
+	if err != nil {
+		panic(err)
+	}
+	ctx := context.Background()
+	p, err := database.Open(ctx, cfg.DatabaseURL, "elder-agent")
+	if err != nil {
+		panic(err)
+	}
+	defer p.Close()
+	path := os.Getenv("DIRECT_CHAT_TEMPLATE_FILE")
+	if path == "" {
+		path = cfg.VolcVoiceChatTemplate
+	}
+	template, err := os.ReadFile(path)
+	if err != nil {
+		panic(err)
+	}
+	s := elderagent.Service{Pool: p, Provider: elderagent.NewClient(cfg.VolcAccessKeyID, cfg.VolcSecretAccessKey, cfg.VolcSessionToken, cfg.VolcRTCBaseURL, cfg.VolcRTCRegion).ForProduct(cfg.VolcHardwareInstanceID, cfg.VolcHardwareProductKey), Template: template, CallbackURL: cfg.SubtitleCallbackURL, CallbackSecret: []byte(cfg.SubtitleCallbackSecret)}
+	info, err := s.Ensure(ctx, *subject)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	fmt.Printf("subject=%s bot_id=%s status=%s\n", *subject, info.BotID, info.Status)
+}