fix: reduce default bloom strength, ensure auto-cycle starts on load

- Default bloom: 0.2 → 0.08, radius 0.25 → 0.2, threshold 0.5 → 0.6
- PostProcessing constructor matches new defaults
- Bump SETTINGS_VERSION to '5' to clear stale localStorage (forces auto scenario)

Co-Authored-By: claude-flow <ruv@ruv.net>

ui/observatory/js/post-processing.js

@@ -77,9 +77,9 @@ export class PostProcessing {
     // Bloom — tuned for green wireframe glow
     this._bloomPass = new UnrealBloomPass(
       new THREE.Vector2(size.x, size.y),
-      1.0,   // strength (less aggressive than before)
-      0.5,   // radius
-      0.25   // threshold
+      0.08,  // strength — subtle glow, overridden by settings
+      0.2,   // radius
+      0.6    // threshold
     );
     this.composer.addPass(this._bloomPass);