Implement report system and fix template task filtering

- Fix template task filtering bug: templates now hidden from all reports
  except 'template' and 'all' reports, even when using custom filters
- Add support for status:template filter to explicitly show templates
- Implement comprehensive report system with 12 predefined reports:
  * active - Started tasks
  * all - All tasks including templates
  * completed - Completed tasks
  * list - Pending tasks (default)
  * minimal - Pending tasks in minimal format
  * newest - Most recent pending tasks
  * oldest - Oldest pending tasks
  * overdue - Overdue tasks
  * ready - Tasks ready to work on
  * recurring - Pending recurring instances
  * template - Recurring template tasks
  * waiting - Hidden/waiting tasks
- Replace list command with report-based architecture
- Add configurable default_report option (defaults to 'list')
- Add minimal display format (ID + description only)
- Support flexible syntax: 'opal <report> [filters]' or 'opal [filters] <report>'
- Add 'opal reports' command to list all available reports

opal-task/cmd/root.go

@@ -23,9 +23,16 @@ const parsedArgsKey contextKey = "parsedArgs"
 
 // Command classification
 var commandNames = []string{
-	"add", "list", "done", "modify", "delete",
+	"add", "done", "modify", "delete",
 	"start", "stop", "count", "projects", "tags",
-	"info", "edit", "server", "sync",
+	"info", "edit", "server", "sync", "reports",
+}
+
+// Report names (dynamically populated)
+var reportNames = []string{
+	"active", "all", "completed", "list", "minimal",
+	"newest", "oldest", "overdue", "ready", "recurring",
+	"template", "waiting",
 }
 
 var commandsWithModifiers = map[string]bool{
@@ -39,9 +46,22 @@ var rootCmd = &cobra.Command{
 	Long: `Opal is a powerful command-line task manager inspired by taskwarrior.
 It supports filtering, tags, priorities, projects, and recurring tasks.`,
 	Run: func(cmd *cobra.Command, args []string) {
-		// Default behavior: list tasks
+		// Default behavior: run configured default report (defaults to "list")
 		parsed := getParsedArgs(cmd)
-		if err := listTasks(parsed.Filters); err != nil {
+
+		// Get default report from config
+		cfg, err := engine.GetConfig()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error loading config: %v\n", err)
+			os.Exit(1)
+		}
+
+		defaultReport := cfg.DefaultReport
+		if defaultReport == "" {
+			defaultReport = "list"
+		}
+
+		if err := runReport(defaultReport, parsed.Filters); err != nil {
 			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
 			os.Exit(1)
 		}
@@ -102,11 +122,12 @@ func preprocessArgs(args []string) *ParsedArgs {
 		}
 	}
 
-	// Find command position
+	// Find command position (check both regular commands and reports)
 	cmdIdx := -1
 	cmdName := ""
 
 	for i, arg := range args {
+		// Check regular commands
 		for _, name := range commandNames {
 			if arg == name {
 				cmdIdx = i
@@ -114,6 +135,16 @@ func preprocessArgs(args []string) *ParsedArgs {
 				break
 			}
 		}
+		// Check report names
+		if cmdIdx < 0 {
+			for _, name := range reportNames {
+				if arg == name {
+					cmdIdx = i
+					cmdName = name
+					break
+				}
+			}
+		}
 		if cmdIdx >= 0 {
 			break
 		}
@@ -159,9 +190,8 @@ func preprocessArgs(args []string) *ParsedArgs {
 func init() {
 	cobra.OnInitialize(initializeApp)
 
-	// Add subcommands
+	// Add regular subcommands
 	rootCmd.AddCommand(addCmd)
-	rootCmd.AddCommand(listCmd)
 	rootCmd.AddCommand(doneCmd)
 	rootCmd.AddCommand(modifyCmd)
 	rootCmd.AddCommand(deleteCmd)
@@ -172,6 +202,13 @@ func init() {
 	rootCmd.AddCommand(tagsCmd)
 	rootCmd.AddCommand(infoCmd)
 	rootCmd.AddCommand(editCmd)
+	rootCmd.AddCommand(reportsCmd)
+
+	// Add report commands dynamically
+	reportCommands := CreateReportCommands()
+	for _, cmd := range reportCommands {
+		rootCmd.AddCommand(cmd)
+	}
 }
 
 func initializeApp() {