quickshell: replace macOS-style shell with standalone overview module

Swap the illogical-impulse-derived components for the upstream
quickshell-overview standalone module, update Hyprland keybinds
(Super+Tab overview, rofi launcher), refresh foot colors and
starship theme, and adjust related host/module wiring.

home/hypr/quickshell/config.json

@@ -0,0 +1,42 @@
+{
+  "appearance": {
+    "colorSource": "default",
+    "rounding": {
+      "unsharpen": 0,
+      "verysmall": 0,
+      "small": 0,
+      "normal": 0,
+      "large": 0,
+      "full": 9999,
+      "screenRounding": 0,
+      "windowRounding": 0
+    },
+    "font": {
+      "family": {
+        "main": "IBM Plex Sans",
+        "title": "Instrument Serif",
+        "expressive": "IBM Plex Sans"
+      },
+      "pixelSize": {
+        "smaller": 11,
+        "small": 13,
+        "normal": 15,
+        "larger": 19,
+        "huge": 24
+      }
+    },
+    "animation": {
+      "duration": {
+        "elementMove": 400,
+        "elementMoveEnter": 400,
+        "elementMoveFast": 200
+      }
+    }
+  },
+  "overview": {
+    "effects": {
+      "enableBackdrop": true,
+      "backdropOpacity": 0.35
+    }
+  }
+}