feat: add thumbnail preview, audio-only detection, /download command, tests, and bugfixes

- Add thumbnail preview with metadata (title, uploader, duration) before download
- Auto-detect audio-only sites (Spotify, SoundCloud, etc.) and skip type selection
- Add /download command for feature parity with UI button
- Fix yt-dlp defer bug: StatusFailed was overwritten to StatusCompleted
- Fix handleURLInput using editText with msgID=0 (now uses sendWithKB)
- Fix filename detection: use job ID prefix for reliable file finding
- Fix double answerCb between handleBackStep and handleDownloadPrompt
- Fix runDownload unused msgID parameter
- Fix context for download goroutine (use context.Background)
- Remove unused startWebhook h parameter
- Remove dead buildToggleKeyboard function
- Add formatBytes, formatDuration, formatLabelForDisplay tests
- Add IsAudioOnlyContent, MediaType.String tests
- Add repo integration tests (users, preferences, quotas, history, delete)
- Add cmd/bot tests (parseAllowedUsers, env helpers)
- Add edge case tests for progress parser
- Add zero/negative safety guard in formatDuration
- Add .gitea, TODO.md, opencode.json to gitignore

cmd/bot/main_test.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestParseAllowedUsers(t *testing.T) {
+	tests := []struct {
+		input string
+		want  map[int64]bool
+	}{
+		{"", map[int64]bool{}},
+		{"12345", map[int64]bool{12345: true}},
+		{"12345,67890", map[int64]bool{12345: true, 67890: true}},
+		{" 12345 , 67890 ", map[int64]bool{12345: true, 67890: true}},
+		{"12345,", map[int64]bool{12345: true}},
+		{",12345", map[int64]bool{12345: true}},
+		{"invalid", map[int64]bool{}},
+	}
+	for _, tt := range tests {
+		got := parseAllowedUsers(tt.input)
+		if len(got) != len(tt.want) {
+			t.Errorf("parseAllowedUsers(%q) = %v, want %v", tt.input, got, tt.want)
+			continue
+		}
+		for k, v := range tt.want {
+			if got[k] != v {
+				t.Errorf("parseAllowedUsers(%q)[%d] = %v, want %v", tt.input, k, got[k], v)
+			}
+		}
+	}
+}
+
+func TestGetEnvDefault(t *testing.T) {
+	t.Setenv("TEST_EXISTS", "hello")
+	if got := getEnvDefault("TEST_EXISTS", "fallback"); got != "hello" {
+		t.Errorf("getEnvDefault() = %q, want %q", got, "hello")
+	}
+	if got := getEnvDefault("TEST_MISSING", "fallback"); got != "fallback" {
+		t.Errorf("getEnvDefault() = %q, want %q", got, "fallback")
+	}
+}
+
+func TestGetEnvIntDefault(t *testing.T) {
+	t.Setenv("TEST_INT", "42")
+	if got := getEnvIntDefault("TEST_INT", 0); got != 42 {
+		t.Errorf("getEnvIntDefault() = %d, want %d", got, 42)
+	}
+	if got := getEnvIntDefault("TEST_MISSING", 99); got != 99 {
+		t.Errorf("getEnvIntDefault() = %d, want %d", got, 99)
+	}
+	if got := getEnvIntDefault("TEST_INT", 0); got != 42 {
+		t.Errorf("getEnvIntDefault() cached = %d, want %d", got, 42)
+	}
+}