RFC 0012: Epic / Tracking issue for interactive TUI mode

[rmanibus]

Context

Track completion and rollout for RFC 0012 (Interactive TUI Mode).

RFC: rfcs/0012-interactive-tui-mode.md

Goal

Provide an interactive terminal UI for backup selection, restore browsing, and repository workflows without introducing background scheduling concerns into the first delivery.

Scope

• Interactive command entry point and TUI application structure.
• Core views for common workflows (backup, restore, snapshot/repo browsing).
• Shared action layer so TUI flows reuse existing CLI/client behavior.
• Documentation and UX guidance for interactive usage.

Explicitly out of scope

• Background scheduling and daemon lifecycle management (RFC 0013).
• Replacing existing non-interactive CLI commands.

Exit criteria

• The main TUI workflows described in the RFC are implemented or intentionally descoped.
• Error handling and recovery paths are usable in an interactive terminal context.
• Docs explain when to use TUI mode vs standard CLI commands.