Add "power" page

Signed-off-by: Hadi <[email protected]>

internal/ui/power/messages.go

@@ -0,0 +1,23 @@
+package power
+
+import "github.com/anotherhadi/settuings/internal/power"
+
+// checkMsg carries the result of power.CheckAvailable (powerprofilesctl).
+type checkMsg struct{ err error }
+
+// tickMsg triggers a periodic refresh of profiles + battery while this page
+// is active.
+type tickMsg struct{}
+
+type profilesMsg struct {
+	profiles []power.Profile
+	err      error
+}
+
+type setProfileMsg struct{ err error }
+
+type batteryMsg struct {
+	batteries []power.Battery
+	ac        power.ACStatus
+	err       error
+}