Merge pull request #1 from ricsdeol/feature/device-ui

feat(phase4): swap device management — Devices tab with swapon/swapoff/reset

Author: ricsdeol

CLAUDE.md

@@ -69,9 +69,9 @@ Phase 4 → swapon/swapoff via nix, devices UI, root check
 Phase 5 → create-swap wizard, tokio::process::Command, disk space validation
 ```
 
-## Before committing
+## After implementing all phases
 
-Run these and fix any issues before creating a commit:
+Run these and fix any issues after implement all phases:
 
 ```bash
 cargo build          # must compile clean (zero warnings)

Cargo.toml

@@ -10,7 +10,7 @@ tokio       = { version = "1.51.1", features = ["full"] }
 tokio-util  = "0.7.18"
 futures     = "0.3.32"
 sysinfo     = "0.38.4"
-nix         = { version = "0.31.2", features = ["process", "signal", "mount"] }
+nix         = { version = "0.31.2", features = ["process", "signal", "mount", "user"] }
 color-eyre  = "0.6.5"
 human_bytes = "0.4.3"
 glob        = "0.3.3"

docs/devices.md

@@ -0,0 +1,57 @@
+# Devices Tab
+
+The Devices tab (press `3` or navigate with `Tab`) shows all active swap devices and lets you activate, deactivate, or reset them.
+
+## Requirements
+
+Control operations (`o`, `f`, `r`) require root. Run as:
+
+```
+sudo swaptop
+```
+
+If you run without root, you can still view device status — only control is restricted.
+
+## Columns
+
+| Column | Description |
+|--------|-------------|
+| Path   | Device path (e.g. `/dev/sda2`, `/swapfile`) |
+| Type   | `Partition`, `File`, `Zram`, or `DynamicPager` |
+| Total  | Total swap capacity |
+| Used   | Currently used swap |
+| %      | Usage percentage |
+| Pri    | Kernel priority (higher = preferred) |
+| Status | `ACTIVE`, `INACTIVE`, `⏳ ...`, `✓ OK`, or `✗ ERROR` |
+
+## Keybindings
+
+| Key         | Action |
+|-------------|--------|
+| `j` / `↓`  | Move selection down |
+| `k` / `↑`  | Move selection up |
+| `o`         | Activate selected device (`swapon`) |
+| `f`         | Deactivate selected device (`swapoff`) |
+| `r`         | Reset selected device (`swapoff` + 100ms + `swapon`) |
+| `s`         | Confirm action (when modal is open) |
+| `Esc`       | Cancel confirmation modal |
+| `Tab` / `1-4` | Switch tabs |
+| `q`         | Quit |
+
+## Status Indicators
+
+- **`ACTIVE`** — device is currently active as swap
+- **`INACTIVE`** — device is known but not currently active
+- **`⏳ ...`** — operation in progress (swapon/swapoff running)
+- **`✓ OK`** — last operation succeeded
+- **`✗ ERROR`** — last operation failed (check statusbar for details)
+
+## Reset Operation
+
+Reset (`r`) performs `swapoff` followed by `swapon` with a 100ms pause. This forces the kernel to move all swap pages back to RAM and then re-enable the device, which clears fragmentation. Use it when swap usage is high but actual data could be consolidated.
+
+**Note:** Reset requires enough free RAM to hold all data currently in that swap device. If RAM is too full, `swapoff` will fail with an error.
+
+## Platform Notes
+
+On **macOS**, swap is managed automatically by `dynamic_pager`. The Devices tab shows the active swapfiles but control operations are unavailable.