Add interactive mode with fuzzy search and hierarchical navigation

[ManUtopiK]

Introduce mask -i / mask --interactive flag that launches a terminal UI for browsing and executing maskfile commands. Uses skim for fuzzy search with preview panel and dialoguer for argument/flag prompts. Supports hierarchical navigation with arrow keys (→ enter subcommands, ← go back). Feature-gated behind the interactive feature (enabled by default, opt-out with --no-default-features).

Which issue does this fix?

Closes #144

Describe the solution

• Add mask -i / mask --interactive flag that launches a terminal UI for browsing and executing maskfile commands
• Fuzzy search powered by https://github.com/lotabout/skim with a preview panel showing description, arguments, flags, and script source
• Hierarchical navigation: → to enter subcommands, ← to go back, breadcrumb trail shown at the top
• After selecting a command, https://github.com/console-rs/dialoguer prompts for required/optional arguments and flags (choices, values, booleans)
• Feature-gated behind the interactive feature (enabled by default, opt-out with --no-default-features to keep the binary lean)

Files changed

File	Description
mask/Cargo.toml	Add skim + dialoguer as optional dependencies
mask/src/main.rs	Add -i/--interactive flag and module wiring
mask/src/interactive.rs	New module: skim selector + dialoguer prompts

Test plan

• cargo build — compiles without errors or warnings
• cargo build --no-default-features — compiles without skim/dialoguer
• cargo test — all existing tests pass (1 pre-existing failure unrelated to this change)
• mask -i — opens interactive selector, fuzzy search works, preview panel shows command details
• Arrow key navigation through subcommands works (→ enter, ← back)
• Selecting a command with Enter executes it
• Esc goes back one level, then quits at root
• mask --help shows the --interactive flag