Gate READY on download completion; move audio to ~/.radiantwave/audio

State machine now uses DOWNLOADING_ASSETS before READY. Downloads closing
the DownloadDone channel signals checkState() to proceed. Download failure
sets downloadFailed flag which prevents READY. Audio files moved from
~/.local/share/rhemawave/audio to ~/.radiantwave/audio/.

Regression tests in application_test.go (linux build-tagged due to
network package D-Bus init). Version 0.6.

internal/application/application_test.go

@@ -0,0 +1,186 @@
+//go:build linux
+
+package application
+
+import (
+	"testing"
+
+	"gorm.io/gorm"
+	"rhemawavetech.com/rhemawave/internal/db"
+	"rhemawavetech.com/rhemawave/internal/page"
+)
+
+// Regression: The app used to reach READY before audio downloads completed,
+// showing "Status: READY" while "0 / 14 Files Downloaded" was still in progress.
+// The fix gates READY on downloadsComplete being true.
+
+// TestStateTransitionsToDownloadingAssets verifies that when all config
+// prerequisites are met but downloads are not complete, the state transitions
+// to DOWNLOADING_ASSETS instead of READY.
+func TestStateTransitionsToDownloadingAssets(t *testing.T) {
+	// Set up minimal application state
+	app := &Application{
+		state:    FIRST_RUN,
+		DB:       setupTestDB(t),
+		running:  true,
+	}
+
+	// Simulate: network is up, email and license are set
+	networkIsUp = true
+	config, err := db.GetConfig(app.DB)
+	if err != nil {
+		t.Fatal(err)
+	}
+	config.EmailAddress = "test@example.com"
+	config.LicenseKey = "test-key-123"
+	app.DB.Save(config)
+
+	// Downloads are NOT complete
+	app.downloadsComplete = false
+
+	// Create a minimal router with channels
+	downloadDone := make(chan struct{})
+	app.PageRouter = &page.Router{
+		Context: page.PageCtx{
+			DbPtr:        app.DB,
+			DownloadDone: downloadDone,
+		},
+	}
+
+	// Run checkState
+	app.checkState()
+
+	// Should be in DOWNLOADING_ASSETS, not READY
+	if app.state != DOWNLOADING_ASSETS {
+		t.Errorf("state = %v, want DOWNLOADING_ASSETS (downloads not complete)", app.state)
+	}
+}
+
+// TestStateTransitionsToReadyWhenDownloadsComplete verifies that the state
+// transitions to READY only after downloads are complete.
+func TestStateTransitionsToReadyWhenDownloadsComplete(t *testing.T) {
+	app := &Application{
+		state:    FIRST_RUN,
+		DB:       setupTestDB(t),
+		running:  true,
+	}
+
+	networkIsUp = true
+	config, err := db.GetConfig(app.DB)
+	if err != nil {
+		t.Fatal(err)
+	}
+	config.EmailAddress = "test@example.com"
+	config.LicenseKey = "test-key-123"
+	app.DB.Save(config)
+
+	// Downloads ARE complete
+	app.downloadsComplete = true
+
+	downloadDone := make(chan struct{})
+	app.PageRouter = &page.Router{
+		Context: page.PageCtx{
+			DbPtr:        app.DB,
+			DownloadDone: downloadDone,
+		},
+	}
+
+	app.checkState()
+
+	if app.state != READY {
+		t.Errorf("state = %v, want READY", app.state)
+	}
+}
+
+// Regression: Download failure should prevent the app from reaching READY.
+// If downloads fail, the user sees an error and must restart to retry.
+func TestDownloadFailurePreventsReady(t *testing.T) {
+	app := &Application{
+		state:    FIRST_RUN,
+		DB:       setupTestDB(t),
+		running:  true,
+	}
+
+	networkIsUp = true
+	config, err := db.GetConfig(app.DB)
+	if err != nil {
+		t.Fatal(err)
+	}
+	config.EmailAddress = "test@example.com"
+	config.LicenseKey = "test-key-123"
+	app.DB.Save(config)
+
+	// Downloads completed but failed
+	app.downloadsComplete = false
+	app.downloadFailed = true
+
+	downloadDone := make(chan struct{})
+	app.PageRouter = &page.Router{
+		Context: page.PageCtx{
+			DbPtr:        app.DB,
+			DownloadDone: downloadDone,
+		},
+	}
+
+	app.checkState()
+
+	// Should NOT be READY — download failed
+	if app.state == READY {
+		t.Error("state should not be READY when download has failed")
+	}
+}
+
+// TestStateStaysReadyOnceSet verifies that once the state reaches READY,
+// checkState() is a no-op (doesn't reset or re-navigate).
+func TestStateStaysReadyOnceSet(t *testing.T) {
+	app := &Application{
+		state:    READY,
+		DB:       setupTestDB(t),
+		running:  true,
+	}
+
+	downloadDone := make(chan struct{})
+	app.PageRouter = &page.Router{
+		Context: page.PageCtx{
+			DbPtr:        app.DB,
+			DownloadDone: downloadDone,
+		},
+	}
+
+	app.checkState()
+
+	if app.state != READY {
+		t.Errorf("state = %v, want READY (should not change once set)", app.state)
+	}
+}
+
+// setupTestDB creates a temporary in-memory SQLite database for testing.
+func setupTestDB(t *testing.T) *gorm.DB {
+	t.Helper()
+	d, err := db.Connect(":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Migrate(d); err != nil {
+		t.Fatal(err)
+	}
+	// Create default config
+	cfg := &db.AppConfig{
+		Model:               gorm.Model{ID: 1},
+		DataDir:             t.TempDir(),
+		AssetsDir:           t.TempDir(),
+		SystemLevel:         "BASIC",
+		SelectedAudioDevice: "default",
+		InitialFontSize:     128,
+		StandardFontSize:    32,
+		LinePattern:         "fibonacci",
+		AudioEnabled:        true,
+		SavedVolume:         1.0,
+		EmailAddress:        "",
+		LicenseKey:          "",
+	}
+	if err := d.Create(cfg).Error; err != nil {
+		t.Fatal(err)
+	}
+	return d
+}