CLAUDE: per-SEQUENCE zero-DC level - fix rotation-synced DC flicker (the rotating ghost)

POSE-10 forensics: RT-RENDER merged horizon pk-pk 234 counts (sky 187) with
the dominant period 165.7 scenes = EXACTLY one camera revolution (21.83 rpm
@ 60 fps -> 164.9); POSE-RT-COMPOSITE real slices the same. Cause: the
per-SCENE zero-DC sky median (Config.dc_level=NaN auto) oscillates with
azimuth as warm terrain sweeps through the sky half; downstream temporal
averages convert the wobble into content-correlated residuals - the faint
rotating ghost ('real image treated as FPN'). Oracle MERGED-DBG shows a
separate, 3-6x smaller wobble at the same period (pre-existing, prepared
path - not addressed here).

Fix (Andrey's rule: one constant per sequence, from the average scene):
- CuasRT.sequenceDcLevel(): manual curt.dc_center override when nonzero,
  else the RT-STATE value derived by appropriateCenter() from the borrowed
  center (= the sequence average) - scenes and center shift by the
  IDENTICAL constant.
- CuasPoseRT (A2 ingest) + CuasRender (render test) now pass a Config with
  that dc_level instead of null; NaN fallback (per-scene) kept but warns
  loudly. Config.dc_level doc updated.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/main/java/com/elphel/imagej/cuas/rt/CuasConditioning.java

@@ -66,7 +66,7 @@ public class CuasConditioning {
 		// NaN = AUTO (the global mean over all sensors of this scene). A calibration-
 		// maintained fixed level (no scene-to-scene DC flicker) is the production target.
 		public boolean zero_dc              = true;   // By Claude on 07/05/2026
-		public double  dc_level             = Double.NaN; // NaN = auto (per-scene global mean) // By Claude on 07/05/2026
+		public double  dc_level             = Double.NaN; // the PER-SEQUENCE constant (CuasRT.sequenceDcLevel - RT-STATE/appropriateCenter). NaN = per-scene sky median FALLBACK ONLY: it oscillates with rotation (terrain sweeps the sky half; 234-count pk-pk @ 1 rev period, POSE-10) and downstream temporal averages turn that into content ghosts. // By Claude on 07/05/2026
 		public Config() {}
 	}
 

src/main/java/com/elphel/imagej/cuas/rt/CuasPoseRT.java

@@ -742,6 +742,19 @@ public class CuasPoseRT {
 				center_CLT.getGeometryCorrection().pixelSize;
 		final double [] px_per_rad = {px_per_rad_at, px_per_rad_at, px_per_rad_r};
 
+		// PER-SEQUENCE DC level for the A2 scene conditioning - NOT per-scene: a per-scene
+		// sky median oscillates with rotation (terrain sweeps the sky half; 234-count pk-pk
+		// at exactly 1 rev period, POSE-10 forensics) and downstream temporal averages turn
+		// it into content ghosts. ONE constant (CuasRT.appropriateCenter derived it from
+		// the borrowed center = the average scene). By Claude on 07/05/2026, Andrey's rule.
+		final CuasConditioning.Config cond_cfg = new CuasConditioning.Config();
+		if (clt_parameters.curt.pose_raw) {
+			cond_cfg.dc_level = CuasRT.sequenceDcLevel(clt_parameters, center_CLT);
+			if (Double.isNaN(cond_cfg.dc_level)) {
+				System.out.println("CuasPoseRT: WARNING - no per-sequence DC level (RT-STATE missing, curt.dc_center==0):"+
+						" falling back to the PER-SCENE sky median (rotation-synced DC flicker!)");
+			}
+		}
 		// ---- Ascending per-scene loop (the RT iterator) ----
 		final int tilesX = center_CLT.getTilesX();
 		final int tilesY = center_CLT.getTilesY();
@@ -861,7 +874,7 @@ public class CuasPoseRT {
 			if (clt_parameters.curt.pose_raw) {
 				final boolean raw_ok = CuasConditioning.conditionSceneToGpu(
 						quadCLTs[nscene],           // QuadCLT scene (jp4 + calibration + FPN)
-						null,                       // Config (defaults: rowcol + photometric + FPN)
+						cond_cfg,                   // Config: defaults + the PER-SEQUENCE dc_level // By Claude on 07/05/2026
 						ImageDtt.THREADS_MAX,       // read threads
 						debugLevel - 2);            // debug
 				if (!raw_ok) {

src/main/java/com/elphel/imagej/cuas/rt/CuasRT.java

@@ -306,6 +306,29 @@ public class CuasRT {
 				") - downstream consumers see the appropriated center only");
 	}
 
+	/**
+	 * Resolve the PER-SEQUENCE DC level for scene conditioning. The fix for the
+	 * rotation-synced DC flicker (POSE-10 forensics, 07/05/2026): a per-SCENE sky median
+	 * oscillates with azimuth as warm terrain sweeps through the sky half - RT-RENDER
+	 * horizon pk-pk 234 counts with the period exactly one camera revolution, and any
+	 * temporal-average step downstream converts that wobble into content-correlated
+	 * residuals ("real image treated as FPN" ghosts). ONE constant per sequence instead
+	 * (Andrey's rule: from the average scene): manual curt.dc_center override when
+	 * nonzero, else the RT-STATE value derived by {@link #appropriateCenter} from the
+	 * borrowed center (which IS the sequence average) - so the scenes and the center
+	 * shift by the IDENTICAL constant.
+	 * @return the level, or NaN when neither source is available (conditioning then
+	 *         falls back to the per-scene median - callers warn loudly).
+	 * By Claude on 07/05/2026.
+	 */
+	public static double sequenceDcLevel(
+			final CLTParameters clt_parameters,
+			final QuadCLT       center_CLT) {
+		if (clt_parameters.curt.dc_center != 0.0) return clt_parameters.curt.dc_center;
+		final CuasRtState state = CuasRtState.load(center_CLT.getX3dDirectory(), center_CLT.getImageName());
+		return (state.dc_center != null) ? state.dc_center : Double.NaN;
+	}
+
 	/**
 	 * Optional EXCLUSIVE diagnostic modes - each replaces the production run. Precedence
 	 * (unchanged from the OpticalFlow inline era): rend_test > pose_test > cond_test.

src/main/java/com/elphel/imagej/cuas/rt/CuasRender.java

@@ -276,6 +276,18 @@ public class CuasRender {
 		System.out.println("testRenderSequence(): motion-blur compensation "+
 				(mb_en ? ("ON (tau="+mb_tau+" s, max gain "+mb_max_gain+") - compare vs the MB oracle DBG") :
 					"OFF - compare vs the -NOMB oracle DBG"));
+		// PER-SEQUENCE DC level for the scene conditioning - NOT per-scene: a per-scene sky
+		// median oscillates with rotation (terrain sweeps the sky half; 234-count pk-pk at
+		// exactly 1 rev period measured in THIS product, POSE-10 forensics) and downstream
+		// temporal averages turn it into content ghosts. ONE constant per sequence
+		// (CuasRT.appropriateCenter derived it from the borrowed center = the average
+		// scene). By Claude on 07/05/2026, Andrey's rule.
+		final CuasConditioning.Config cond_cfg = new CuasConditioning.Config();
+		cond_cfg.dc_level = CuasRT.sequenceDcLevel(clt_parameters, center_CLT);
+		if (Double.isNaN(cond_cfg.dc_level)) {
+			System.out.println("testRenderSequence(): WARNING - no per-sequence DC level (RT-STATE missing, curt.dc_center==0):"+
+					" falling back to the PER-SCENE sky median (rotation-synced DC flicker!)");
+		}
 		final ArrayList<float [][]> rendered = new ArrayList<float [][]>();
 		final ArrayList<String>     ts_names = new ArrayList<String>();
 		final float [] nan_slice = new float [img_width * img_height];
@@ -301,7 +313,7 @@ public class CuasRender {
 				// borrowed (stored); in production they come analytically from pose + rpm.
 				final boolean raw_ok = CuasConditioning.conditionSceneToGpuCuas(
 						quadCLTs[nscene],
-						null,                 // Config (defaults: rowcol + photometric + FPN)
+						cond_cfg,             // Config: defaults + the PER-SEQUENCE dc_level // By Claude on 07/05/2026
 						(ers_atr_dt != null) ? ers_atr_dt : ZERO3.clone(), // omegas
 						(ers_xyz_dt != null) ? ers_xyz_dt : ZERO3.clone(), // velocities (provision)
 						ImageDtt.THREADS_MAX,