feat(themes): boreal-dawn — the light half of the boreal day/night pair

First of three Nomarchy-exclusive dark/light pairs for v1 (with
executive-ivory and kiln/kiln-clay in the next commits), built for
settings.autoTheme: same identity in two lights, so the sunrise flip
feels like the same room brightening.

Boreal Dawn is the boreal forest six hours later — the aurora faded
into a cold clear dawn. Frost-paper base (#EDF2F6), deep-slate text
(10.9:1 AAA), the aurora violet deepened to text-grade (#7458C8,
4.69:1), spruce teal accentAlt (#22766E), GeistMono + the same 6/14/3/12
geometry as boreal so the pair swaps shape-invariant. Assets: whole-swap
waybar (the same three frosted pills, light glass), rofi + 4x3 launcher
grid, btop theme, dawn-treeline wallpaper mirroring aurora-boreal's
composition (same spiky silhouette, dawn gradient, fading stars).

flake.lock: nomarchy-wallpapers 803b48d -> a716cf6 — the single-input
bump carrying backgrounds for all four new slugs (this task is the lock
bump). Preview is a real render: theme-shot VM desktop at 480x270.

Verification: V2. nix flake check --no-build green; checks
theme-contrast (28x7+chips), theme-wholeswap, waybar-language,
waybar-swap-env, rofi-text-width, state-sync-validate, auto-theme (VM
day/night engine) all green. Visual protocol: theme-shot VM renders
viewed for desktop + menu (frosted pills, wash selection, legibility —
screenshots in /nix/store/l26kfdcf...theme-shot-boreal-dawn). audit
findings at/below the boreal baseline (CVD-only + the same
accent-pair Δhue as boreal). V3 pending: real-GL blur, btop visual,
launcher grid on hardware (HARDWARE-QUEUE, this batch's entry).

Design by Fable (palette lab + wallpaper SVGs); asset port by a Sonnet
subagent from the boreal sources; reviewed file-by-file on Fable.

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

themes/boreal-dawn/rofi.rasi

@@ -0,0 +1,122 @@
+/**
+ * Boreal Dawn — rofi whole-swap (themes/<slug>/rofi.rasi).
+ * The base theme: a frosted dawn panel used by every menu (and, as a
+ * list, the fallback launcher). The app launcher reshapes this into a
+ * grid via themes/boreal-dawn/launcher.rasi, which @imports this file. The
+ * `configuration {}` block is omitted on purpose — it comes from
+ * modules/home/rofi.nix. Element structure mirrors the generated theme
+ * so the theme-grid picker's per-invocation -theme-str still lays out.
+ */
+
+* {
+    base:      #EDF2F6;
+    glassBg:   #EDF2F6E6;
+    surface:   #DFE7EE;
+    overlay:   #A9B8C6;
+    text:      #333E4E;
+    subtext:   #51617A;
+    muted:     #7C8B9D;
+    accent:    #7458C8;
+    accentAlt: #22766E;
+    accentSoft: #7458C83B;
+    frostEdge: #22766E5C;
+
+    font: "GeistMono Nerd Font 11";
+    background-color: transparent;
+    text-color: @text;
+}
+
+window {
+    background-color: @glassBg;
+    border: 1px;
+    border-color: @frostEdge;
+    border-radius: 14px;
+    width: calc( 84ch min 65% );
+    location: center;
+    anchor: center;
+    padding: 16px;
+}
+
+mainbox {
+    background-color: transparent;
+    children: [ inputbar, message, listview ];
+    spacing: 12px;
+}
+
+inputbar {
+    children: [ prompt, entry ];
+    background-color: @surface;
+    text-color: @text;
+    border-radius: 10px;
+    padding: 12px 16px;
+    spacing: 10px;
+}
+
+prompt { text-color: @accent; }
+
+entry {
+    text-color: @text;
+    cursor: text;
+    placeholder: "Search…";
+    placeholder-color: @muted;
+}
+
+listview {
+    background-color: transparent;
+    columns: 1;
+    lines: 8;
+    dynamic: true;
+    scrollbar: true;
+    spacing: 6px;
+    padding: 4px 0px 0px 0px;
+}
+
+element {
+    background-color: transparent;
+    text-color: @text;
+    orientation: horizontal;
+    border-radius: 10px;
+    padding: 10px 14px;
+    spacing: 12px;
+}
+
+element normal.normal,
+element alternate.normal {
+    background-color: transparent;
+}
+
+/* Selected row lifts on a soft aurora-violet wash. */
+element selected.normal {
+    background-color: @accentSoft;
+    text-color: @text;
+}
+
+element-icon {
+    background-color: transparent;
+    size: 30px;
+    cursor: inherit;
+}
+
+element-text {
+    background-color: transparent;
+    text-color: inherit;
+    highlight: bold;
+    vertical-align: 0.5;
+}
+
+message { padding: 0px; }
+
+textbox {
+    background-color: @surface;
+    text-color: @text;
+    border-radius: 10px;
+    padding: 10px 14px;
+}
+
+scrollbar {
+    width: 4px;
+    handle-width: 4px;
+    handle-color: @accent;
+    background-color: @surface;
+    border: 0px;
+}