docs: -i interactive TUI convention in local/AGENTS.md

All Red Bear desktop apps use -i/--interactive for TUI mode.
Pattern: ratatui 0.30 + termion, feature-gated behind 'tui' feature.
Apps: cub, redbear-info, redbear-netctl.

local/AGENTS.md

@@ -1,5 +1,23 @@
 # RED BEAR OS — DERIVATIVE OF REDOX OS
 
+## TUI CONVENTION — `-i` INTERACTIVE SWITCH
+
+All Red Bear desktop applications that offer a TUI mode MUST use `-i`/`--interactive`
+as the standard switch. Applications without a subcommand default to launching their TUI.
+
+| App | TUI | `-i` flag | Description |
+|-----|-----|-----------|-------------|
+| `cub` | ratatui | ✅ | AUR package manager (search/info/install/build/query tabs) |
+| `redbear-info` | ratatui | ✅ | System dashboard (System/Hardware/Network/Integrations/Health tabs) |
+| `redbear-netctl` | ratatui | ✅ | Network profile manager console |
+
+**Pattern:**
+- `app` (no args) → launches TUI if terminal available, else help
+- `app -i` → launches TUI regardless
+- `app <command>` → CLI mode
+- Feature-gate TUI behind `tui` feature in Cargo.toml for minimal builds
+- Use `ratatui 0.30 + termion` (same stack as cub-tui)
+
 This directory contains ALL custom work on top of mainline Redox. When mainline Redox
 updates (`git pull` on the build system repo), this directory is untouched.