feat(view): the moon in its phase over the "Follow the Sun" background (#661)

At dawn, dusk and night the environment shows the moon in the top-left
corner of the scene, behind the plan: computed in the card from the home
coordinates and the browser clock (short Meeus series + topocentric
parallax, within 1.4° / 1.8 pp of JPL Horizons), one designer image under
a continuous phase mask with the lit side always on the left (owner
2026-09-29), a feathered terminator, 3°/3 % thresholds and the 2 s fade of
the window rays. Everything but a small gate lives in the lazy
moon-runtime chunk, with its own 30 s ticker. General settings: "Sun"
becomes "Sun and Moon" with one switch, on for new installations
(DEFAULT_CONFIG), off for existing ones.

The initial View graph sat 728 B under its budget: the gate is paid for by
moving fifteen dialog-only strings of General settings into the lazy
settings dictionary (#459) and by one build fingerprint literal instead of
three, so the graph ends 4 B above dev. Golden: two new moon scenes, and
the two General settings help frames show «Sun and Moon»; the WSL artifact
test fixture now models scenes whose first capture awaits acceptance.

Issue: #661
User-Visible: yes
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018qZfe7YS4rqEMKoVeS3GKd

src/editor-runtime-loader.ts

@@ -1,5 +1,8 @@
 export type EditorRuntimeLoaderState = 'idle' | 'loading' | 'ready' | 'failed';
 
+/** This build's id, embedded at build time; every lazy runtime must carry the same. */
+export const ENTRY_BUILD_FINGERPRINT = '__HOUSEPLAN_SOURCE_FINGERPRINT__';
+
 export interface EditorRuntimeModule<Runtime> {
   readonly fingerprint: string;
   create(): Runtime;