Add task management commands to CLI

Implement task add and task move subcommands for managing tasks in TASKS.md.

task add <slug> <title> [--section <section>]:
- Adds a task to the specified section (default: Inbox)
- Valid sections: Inbox, Proximo, En curso, Bloqueado, En espera, Hecho
- Creates section if it doesn't exist

task move <slug> <task_title> <to_section>:
- Searches for task by title across all sections
- Moves task to destination section
- Marks task as completed ([x]) when moved to Hecho
- Updates checkbox state based on destination

Includes parsing and building functions for TASKS.md with:
- Section normalization (English to Spanish names)
- Merge support for duplicate normalized sections
- Standard section ordering

Uses app.add_typer to register task subcommand group.

tracker/cli/main.py

@@ -12,6 +12,8 @@ from tracker.cli.commands import (
     add_change,
     suggest_next,
     review,
+    task_add,
+    task_move,
 )
 
 app = typer.Typer(
@@ -19,6 +21,14 @@ app = typer.Typer(
     help="Personal Project Tracker CLI - Track your projects with Markdown and YAML",
 )
 
+# Sub-command group for task management
+task_app = typer.Typer(help="Task management commands")
+
+
+# Register task subcommands
+task_app.command("add")(task_add)
+task_app.command("move")(task_move)
+
 
 # Register all commands
 app.command("init-project")(init_project)
@@ -30,6 +40,7 @@ app.command("stop")(stop_session)
 app.command("change")(add_change)
 app.command("next")(suggest_next)
 app.command("review")(review)
+app.add_typer(task_app, name="task")
 
 
 @app.callback()