feat: add clean command to remove temp files, logs, and cached data

Adds `unarr clean` with interactive confirmation, --dry-run, --yes,
and --all flags. Safely skips recent usenet resume files (<7 days) to
preserve download progress. Includes platform-specific PID detection
(Unix signal 0 / Windows heartbeat heuristic), CleanableBytes callback
for future heartbeat reporting, and uses shared ui.FormatBytes.

internal/cmd/clean_test.go

@@ -0,0 +1,177 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestDirStats_Empty(t *testing.T) {
+	dir := t.TempDir()
+	files, bytes := dirStats(dir)
+	if files != 0 || bytes != 0 {
+		t.Errorf("expected 0 files 0 bytes, got %d files %d bytes", files, bytes)
+	}
+}
+
+func TestDirStats_WithFiles(t *testing.T) {
+	dir := t.TempDir()
+	os.WriteFile(filepath.Join(dir, "a.log"), []byte("hello"), 0o644)
+	os.WriteFile(filepath.Join(dir, "b.log"), []byte("world!"), 0o644)
+
+	files, bytes := dirStats(dir)
+	if files != 2 {
+		t.Errorf("expected 2 files, got %d", files)
+	}
+	if bytes != 11 {
+		t.Errorf("expected 11 bytes, got %d", bytes)
+	}
+}
+
+func TestDirStats_NonExistent(t *testing.T) {
+	files, bytes := dirStats("/nonexistent-dir-12345")
+	if files != 0 || bytes != 0 {
+		t.Errorf("expected 0/0 for nonexistent dir, got %d/%d", files, bytes)
+	}
+}
+
+func TestFileSize_Exists(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "test.txt")
+	os.WriteFile(path, []byte("1234567890"), 0o644)
+
+	size := fileSize(path)
+	if size != 10 {
+		t.Errorf("expected 10, got %d", size)
+	}
+}
+
+func TestFileSize_NonExistent(t *testing.T) {
+	size := fileSize("/nonexistent-file-12345")
+	if size != 0 {
+		t.Errorf("expected 0 for nonexistent file, got %d", size)
+	}
+}
+
+
+func TestRunClean_DryRun(t *testing.T) {
+	err := runClean(true, false, false)
+	if err != nil {
+		t.Logf("runClean dry-run returned: %v (may be expected)", err)
+	}
+}
+
+func TestShortenHome(t *testing.T) {
+	home, _ := os.UserHomeDir()
+	if home == "" {
+		t.Skip("no home dir")
+	}
+
+	result := shortenHome(filepath.Join(home, ".local", "share", "unarr", "unarr.log"))
+	if !strings.HasPrefix(result, "~") {
+		t.Errorf("expected path starting with ~, got %q", result)
+	}
+	if strings.Contains(result, home) {
+		t.Errorf("home dir not shortened in %q", result)
+	}
+}
+
+func TestShortenHome_NoHome(t *testing.T) {
+	result := shortenHome("/tmp/some/file.txt")
+	if result != "/tmp/some/file.txt" {
+		t.Errorf("expected unchanged path, got %q", result)
+	}
+}
+
+func TestScanResumeFiles_Empty(t *testing.T) {
+	dir := t.TempDir()
+	found, skipped := scanResumeFiles(dir, false)
+	if len(found) != 0 || skipped != 0 {
+		t.Errorf("expected all zeros, got found=%d skipped=%d", len(found), skipped)
+	}
+}
+
+func TestScanResumeFiles_NonExistent(t *testing.T) {
+	found, skipped := scanResumeFiles("/nonexistent-resume-dir", false)
+	if len(found) != 0 || skipped != 0 {
+		t.Errorf("expected all zeros for nonexistent dir")
+	}
+}
+
+func TestScanResumeFiles_OnlyStale(t *testing.T) {
+	dir := t.TempDir()
+
+	// Create a stale file (>7 days)
+	stalePath := filepath.Join(dir, "old-task.progress")
+	os.WriteFile(stalePath, []byte("stale data"), 0o644)
+	staleTime := time.Now().Add(-8 * 24 * time.Hour)
+	os.Chtimes(stalePath, staleTime, staleTime)
+
+	// Create a fresh file (<7 days)
+	os.WriteFile(filepath.Join(dir, "new-task.progress"), []byte("fresh"), 0o644)
+
+	// Default mode: only stale files
+	found, skipped := scanResumeFiles(dir, false)
+	if len(found) != 1 {
+		t.Errorf("expected 1 stale file, got %d", len(found))
+	}
+	if skipped != 1 {
+		t.Errorf("expected 1 skipped (fresh), got %d", skipped)
+	}
+	if len(found) != 1 || found[0].path != stalePath {
+		t.Errorf("expected stale file in found, got %v", found)
+	}
+}
+
+func TestScanResumeFiles_AllMode(t *testing.T) {
+	dir := t.TempDir()
+
+	// Create stale + fresh files
+	os.WriteFile(filepath.Join(dir, "old-task.progress"), []byte("stale"), 0o644)
+	staleTime := time.Now().Add(-8 * 24 * time.Hour)
+	os.Chtimes(filepath.Join(dir, "old-task.progress"), staleTime, staleTime)
+
+	os.WriteFile(filepath.Join(dir, "new-task.nzb"), []byte("fresh"), 0o644)
+
+	// --all mode: everything
+	found, skipped := scanResumeFiles(dir, true)
+	if len(found) != 2 {
+		t.Errorf("expected 2 files with --all, got %d", len(found))
+	}
+	if skipped != 0 {
+		t.Errorf("expected 0 skipped with --all, got %d", skipped)
+	}
+}
+
+func TestScanResumeFiles_DescLabels(t *testing.T) {
+	dir := t.TempDir()
+
+	// Stale file
+	stalePath := filepath.Join(dir, "old.progress")
+	os.WriteFile(stalePath, []byte("x"), 0o644)
+	staleTime := time.Now().Add(-10 * 24 * time.Hour)
+	os.Chtimes(stalePath, staleTime, staleTime)
+
+	// Fresh file
+	freshPath := filepath.Join(dir, "new.nzb")
+	os.WriteFile(freshPath, []byte("y"), 0o644)
+
+	// Default: stale only
+	found, _ := scanResumeFiles(dir, false)
+	if len(found) != 1 || found[0].desc != "stale resume file" {
+		t.Errorf("expected desc 'stale resume file', got %q", found[0].desc)
+	}
+
+	// All mode: fresh file should say "resume file"
+	found, _ = scanResumeFiles(dir, true)
+	for _, e := range found {
+		if e.path == freshPath && e.desc != "resume file" {
+			t.Errorf("expected desc 'resume file' for fresh file, got %q", e.desc)
+		}
+		if e.path == stalePath && e.desc != "stale resume file" {
+			t.Errorf("expected desc 'stale resume file' for stale file, got %q", e.desc)
+		}
+	}
+}