Glow is the default fill for new spaces, and leads the options list

Owner call: 'Свет по источникам' is the mode that sells the card, so a new
space starts with it and the settings dialog offers it first. Deliberately
NOT changed: the fallback for an absent fill_mode stays 'none'
(spaceDisplayOf), so updating the card never repaints an existing plan
whose owner made no choice. smoke_space_settings re-pinned to the new
contract.

demo/smoke_space_settings.mjs

@@ -56,6 +56,8 @@ checkAll(res, {
   "livingStyle": "--room-stroke:#ff8800;--room-stroke-op:0.8;--room-fill:#ffd45c;--room-fill-op:0.180",
   "lqiFills": 0,
   "atticSquare": true,
-  "atticSettings": {"show_borders": true, "show_names": true, "room_color": "#3ea6ff", "room_opacity": 0.55, "fill_mode": "none", "temp_min": 20, "temp_max": 25, "show_lqi": true, "label_temp": false, "label_hum": false, "label_lqi": false, "label_light": false},
+  // fill_mode 'glow' — the default for NEW spaces since v1.54 (owner call).
+  // Existing spaces with an absent fill_mode still resolve to 'none'.
+  "atticSettings": {"show_borders": true, "show_names": true, "room_color": "#3ea6ff", "room_opacity": 0.55, "fill_mode": "glow", "temp_min": 20, "temp_max": 25, "show_lqi": true, "label_temp": false, "label_hum": false, "label_lqi": false, "label_light": false},
 });
 await finish(browser, res);

src/houseplan-card.ts

@@ -3266,7 +3266,7 @@ class HouseplanCard extends LitElement {
         mode, title: '', planUrl: null, planFile: null,
         source: 'file',
         showBorders: false, showNames: false,
-        roomColor: DEFAULT_ROOM_COLOR, roomOpacity: DEFAULT_ROOM_OPACITY, fillMode: 'none',
+        roomColor: DEFAULT_ROOM_COLOR, roomOpacity: DEFAULT_ROOM_OPACITY, fillMode: 'glow',
         tempMin: DEFAULT_TEMP_MIN, tempMax: DEFAULT_TEMP_MAX,
         showLqi: this._config?.show_signal ?? true,
         cardFontScale: 1,
@@ -3599,7 +3599,7 @@ class HouseplanCard extends LitElement {
       mode: 'create', title, planUrl: null, planFile: null,
       source: 'file',
       showBorders: false, showNames: false,
-      roomColor: DEFAULT_ROOM_COLOR, roomOpacity: DEFAULT_ROOM_OPACITY, fillMode: 'none',
+      roomColor: DEFAULT_ROOM_COLOR, roomOpacity: DEFAULT_ROOM_OPACITY, fillMode: 'glow',
       tempMin: DEFAULT_TEMP_MIN, tempMax: DEFAULT_TEMP_MAX,
       showLqi: this._config?.show_signal ?? true,
       cardFontScale: 1,

src/logic.ts

@@ -617,7 +617,11 @@ export type TapAction = 'info' | 'more-info' | 'toggle' | 'run';
 export const DISPLAY_MODES = ['badge', 'ripple', 'icon_ripple', 'value'] as const;
 export const TAP_ACTIONS = ['info', 'more-info', 'toggle', 'run'] as const;
 /** Space-level fill: 'glow' is a whole-space light model, not a per-room one. */
-export const SPACE_FILL_MODES = ['none', 'lqi', 'light', 'temp', 'glow'] as const;
+// 'glow' leads: it is the default for new spaces since v1.54 — the owner's
+// call, it sells the card best. Existing configs keep whatever they chose;
+// an absent fill_mode still falls back to 'none' (spaceDisplayOf), so an
+// update never repaints somebody's plan.
+export const SPACE_FILL_MODES = ['glow', 'none', 'lqi', 'light', 'temp'] as const;
 export const ROOM_FILL_MODES = ['none', 'lqi', 'light', 'temp'] as const;
 
 export const TOGGLE_SAFE_DOMAINS = new Set(['light', 'switch', 'fan', 'humidifier', 'cover', 'valve']);