feat: refine UI, improve UX, optimize the analysis pipeline, and add character standing positions

lib/prompts/novel-promotion/agent_storyboard_detail.en.txt

@@ -12,6 +12,8 @@ Location info:
 
 Task:
 For each panel, output a complete panel object with improved cinematic detail.
+If any character already has `slot`, prefer preserving it exactly and use it as a preferred placement anchor.
+Treat `slot` as one full placement phrase from the location context, not as a short token.
 
 Required fields per panel:
 - panel_number
@@ -30,7 +32,7 @@ Output schema example (field names must be preserved):
   {
     "panel_number": 1,
     "description": "panel description",
-    "characters": [{ "name": "Character", "appearance": "appearance" }],
+    "characters": [{ "name": "Character", "appearance": "appearance", "slot": "the position beneath the throne steps at the center of the hall" }],
     "location": "location name",
     "scene_type": "daily",
     "source_text": "source text excerpt",
@@ -46,5 +48,9 @@ Rules:
 2. Keep source_text semantically aligned with input; do not rewrite story meaning.
 3. video_prompt should be motion-ready and concrete.
 4. Prefer age+gender wording in video_prompt when naming actors in camera directions.
-5. Return JSON array only.
-6. ⚠️ JSON SAFETY: All quotation marks in text (""''「」 etc.) MUST be converted to corner brackets「」in JSON string values. NEVER use raw ASCII double quotes " inside string values.
+5. Preserve every input `slot` when the character is stably positioned, and reflect it as a preferred anchor in refined description/video_prompt.
+6. `slot` is not an absolute boundary. If the shot is clearly about movement, entry/exit, path traversal, transition space, temporary space, empty space, imagination, dream, memory, or abstract/non-literal space, you may remove `slot` or keep it without forcing a rigid static match.
+7. When no `slot` is used, decide placement freely from source text, action flow, spatial logic, and cinematic staging.
+8. Do not shorten, rewrite, summarize, or replace a provided `slot` phrase with a short token.
+9. Return JSON array only.
+10. ⚠️ JSON SAFETY: All quotation marks in text (""''「」 etc.) MUST be converted to corner brackets「」in JSON string values. NEVER use raw ASCII double quotes " inside string values.