feat: add remote.cache-dir taskrc option

[vmaerten]

Summary

Add support for configuring the remote Taskfiles cache directory via the .taskrc.yml configuration file and a new --remote-cache-dir CLI flag.

This has been ask here: #1317 (comment)

Changes

• Add remote.cache-dir option to taskrc configuration
• Add --remote-cache-dir CLI flag
• Update shell completions (bash, zsh, fish, powershell)
• Update documentation

Configuration priority (highest to lowest)

1. --remote-cache-dir CLI flag
2. remote.cache-dir in .taskrc.yml
3. TASK_REMOTE_DIR environment variable
4. Default: .task

Example

# .taskrc.yml
remote:
  cache-dir: ~/.task

# Or via CLI
task --remote-cache-dir ~/.task my-task

The path can be absolute (e.g., /var/cache/task) or relative to the Taskfile directory.