feat(themes): executive-ivory gets the launcher grid — pair parity with 26dc6f6

Upstream gave executive-slate the boreal-style 4x3 icon-grid launcher
while this batch was in flight; the ivory day sibling follows in the
same push so the pair stays shape-invariant. Geometry identical to the
slate grid (pure layout over the ivory rofi.rasi panel; the selected
card keeps the accent-edge highlight).

Verification: V1 here (layout-only file, colors inherited) + the
re-run checks on the rebased tree in this push; launcher grid on real
hardware is already in the batch HARDWARE-QUEUE entry.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

themes/executive-ivory/launcher.rasi

@@ -0,0 +1,46 @@
+/**
+ * Executive Ivory — app-launcher override (themes/<slug>/launcher.rasi).
+ * Installed to ~/.local/share/rofi/themes/launcher.rasi and used only by
+ * `rofi -show drun` (the SUPER+Space / SUPER+D launcher). It inherits the
+ * flat ivory panel from the sibling rofi.rasi (this whole-swap theme,
+ * which HM deploys under its source basename — rofi.rasi — not custom.rasi),
+ * then reshapes the list into a 4×3 grid of large application icons —
+ * the same grid the executive-slate night sibling ships, so the pair
+ * swaps shape-invariant. Text menus keep the list — they don't use this
+ * theme. Cards stay at the theme's 4px radius (sharp "control panel"
+ * identity), and the selected card keeps the one-accent-edge highlight
+ * from rofi.rasi.
+ */
+
+@import "rofi.rasi"
+
+window { width: 780px; }
+
+listview {
+    columns: 4;
+    lines: 3;
+    fixed-columns: true;
+    spacing: 10px;
+    padding: 6px 0px 0px 0px;
+    /* Fill row-by-row so Down at a column's foot pages to the next screen
+       instead of jumping to the top of the next column (rofi's default
+       Vertical flow). Mirrors the theme-picker grid in rofi.nix. */
+    flow: horizontal;
+}
+
+element {
+    orientation: vertical;
+    padding: 16px 8px;
+    spacing: 10px;
+    border-radius: 4px;
+}
+
+element-icon {
+    size: 56px;
+    horizontal-align: 0.5;
+}
+
+element-text {
+    horizontal-align: 0.5;
+    vertical-align: 0.5;
+}