Synchronize pair cast metadata

docs/prompt-architecture-improvement-plan.md

@@ -273,7 +273,7 @@ Already isolated:
   caption-part joining, embedded soft/hard row output synchronization, and row
   sanitation before metadata leaves generation. It also copies side-specific
   pair metadata, such as soft partner styling and hardcore clothing/detail
-  state, onto the embedded soft/hard rows.
+  state, plus shared cast descriptors, onto the embedded soft/hard rows.
 - final custom-row assembly now lives in `row_assembly.py` behind
   `CustomRowAssemblyRequest`, covering render context population,
   prompt/caption rendering delegation, row-base indexing, row metadata copying,
@@ -326,8 +326,9 @@ Already isolated:
   Embedded soft/hard rows are synchronized to the final pair prompt, caption,
   and negative outputs during normalization so serialized pair metadata does
   not carry stale standalone row text. Side-specific structured fields are
-  synchronized there too, including soft partner styling and hardcore clothing
-  continuity metadata.
+  synchronized there too, including soft partner styling, hardcore clothing
+  continuity metadata, and shared cast descriptors for same-cast caption and
+  formatter routes.
 
 ### Krea2 Formatter Path
 

docs/prompt-pool-routing-map.md

@@ -536,7 +536,7 @@ plain prompt text. When debugging, inspect these fields before editing pools.
 | `options` | `SxCP Insta/OF Options` | Formatters/debug | Soft/hard level, cast mode, continuity, camera modes, expression settings. |
 | `shared_descriptor` | `pair_cast.py` | Pair formatters | Primary creator descriptor. |
 | `shared_cast_descriptors` | `pair_cast.py` | Pair formatters | Full cast descriptor list. |
-| `softcore_row`, `hardcore_row` | Pair route | Pair formatters | Full normal metadata rows for each side; their prompt, caption, negative, and side-specific metadata fields are synchronized to the final pair outputs/root fields during pair normalization. |
+| `softcore_row`, `hardcore_row` | Pair route | Pair formatters | Full normal metadata rows for each side; their prompt, caption, negative, shared cast descriptors, and side-specific metadata fields are synchronized to the final pair outputs/root fields during pair normalization. |
 | `softcore_prompt`, `hardcore_prompt` | `pair_output.py` | Direct output/fallback | Raw pair prompts before formatter rewrite. |
 | `softcore_negative_prompt`, `hardcore_negative_prompt` | `pair_output.py` | Formatter negatives | Separate negatives for each side. |
 | `softcore_partner_styling` | `pair_cast.py` | Krea/SDXL pair branch | Partner softcore clothing and pose when same-cast softcore is enabled. |