Fix dynamic memoir image limits

api/tasks/memoir_tasks.py

@@ -168,6 +168,34 @@ def chapter_has_images_to_generate(images: list[dict] | None) -> bool:
     )
 
 
+def _select_placeholders_for_effective_max(
+    placeholders: list[dict],
+    existing_images: list[dict] | None,
+    effective_max: int,
+) -> list[dict]:
+    existing_placeholders = {
+        item.get("placeholder")
+        for item in normalize_image_assets(existing_images)
+        if item.get("placeholder")
+    }
+    existing_count_in_content = sum(
+        1 for item in placeholders if item.get("placeholder") in existing_placeholders
+    )
+    remaining_new_slots = max(0, effective_max - existing_count_in_content)
+
+    selected: list[dict] = []
+    for item in placeholders:
+        if item.get("placeholder") in existing_placeholders:
+            selected.append(item)
+            continue
+        if remaining_new_slots <= 0:
+            continue
+        selected.append(item)
+        remaining_new_slots -= 1
+
+    return [{**item, "index": index} for index, item in enumerate(selected)]
+
+
 def initialize_chapter_images(chapter) -> list[dict]:
     """Parse IMAGE placeholders from chapter content and build pending image assets."""
     settings = MemoirImageSettings.from_env()
@@ -177,7 +205,13 @@ def initialize_chapter_images(chapter) -> list[dict]:
         return chapter.images
 
     prompt_service = MemoirImagePromptService(llm=None, settings=settings)
-    placeholders = parse_image_placeholders(chapter.content, settings.max_per_chapter)
+    effective_max = settings.effective_max_images(len(chapter.content or ""))
+    all_placeholders = parse_image_placeholders(chapter.content, max_images=None)
+    placeholders = _select_placeholders_for_effective_max(
+        placeholders=all_placeholders,
+        existing_images=chapter.images,
+        effective_max=effective_max,
+    )
     style = prompt_service.CATEGORY_STYLE_MAP.get(chapter.category, settings.default_style)
     chapter.images = _merge_chapter_image_assets(
         existing_images=chapter.images,
@@ -188,8 +222,10 @@ def initialize_chapter_images(chapter) -> list[dict]:
         now_iso=datetime.now(timezone.utc).isoformat(),
     )
     logger.info(
-        "章节图片初始化完成: chapter=%s, placeholders=%d, images=%d, statuses=%s",
+        "章节图片初始化完成: chapter=%s, effective_max=%d, total_placeholders=%d, selected_placeholders=%d, images=%d, statuses=%s",
         chapter.id,
+        effective_max,
+        len(all_placeholders),
         len(placeholders),
         len(chapter.images or []),
         [item.get("status") for item in (chapter.images or [])],