Restore semantic duplicate check at 0.90 threshold, 200-char minimum

Raises body character limit from 80 → 200 (skips short/stub notes)
and threshold from 0.87 → 0.90 (only flags near-identical content).

Enemy design notes sharing a template will pass through cleanly;
accidentally duplicated notes with the same detailed content will
still trigger the confirmation prompt.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/tools.py

@@ -825,6 +825,15 @@ async def execute_tool(user_id: int, tool_name: str, arguments: dict) -> dict:
                 item_type = "task" if near.status is not None else "note"
                 return {"success": False, "requires_confirmation": True, "similar_note": {"id": near.id, "title": near.title}, "error": f"A {item_type} with a very similar title '{near.title}' already exists (similarity: {ratio:.0%}). Ask the user to confirm before creating a separate entry."}
 
+            if not arguments.get("confirmed") and len(task_body.strip()) >= 200:
+                from fabledassistant.services.embeddings import semantic_search_notes as _ssn
+                sem_query = f"{task_title}\n{task_body}".strip()
+                sem_hits = await _ssn(user_id, sem_query, limit=3, threshold=0.90)
+                if sem_hits:
+                    best_score, best_note = sem_hits[0]
+                    item_type = "task" if best_note.status is not None else "note"
+                    return {"success": False, "requires_confirmation": True, "similar_note": {"id": best_note.id, "title": best_note.title}, "error": f"A {item_type} with very similar content exists: '{best_note.title}' (semantic similarity: {best_score:.0%}). Ask the user to confirm before creating a separate entry."}
+
             note = await create_note(
                 user_id=user_id,
                 title=task_title,
@@ -894,6 +903,15 @@ async def execute_tool(user_id: int, tool_name: str, arguments: dict) -> dict:
                 item_type = "task" if near.status is not None else "note"
                 return {"success": False, "requires_confirmation": True, "similar_note": {"id": near.id, "title": near.title}, "error": f"A {item_type} with a very similar title '{near.title}' already exists (similarity: {ratio:.0%}). Ask the user to confirm before creating a separate entry."}
 
+            if not arguments.get("confirmed") and len(note_body.strip()) >= 200:
+                from fabledassistant.services.embeddings import semantic_search_notes as _ssn
+                sem_query = f"{note_title}\n{note_body}".strip()
+                sem_hits = await _ssn(user_id, sem_query, limit=3, threshold=0.90)
+                if sem_hits:
+                    best_score, best_note = sem_hits[0]
+                    item_type = "task" if best_note.status is not None else "note"
+                    return {"success": False, "requires_confirmation": True, "similar_note": {"id": best_note.id, "title": best_note.title}, "error": f"A {item_type} with very similar content exists: '{best_note.title}' (semantic similarity: {best_score:.0%}). Ask the user to confirm before creating a separate entry."}
+
             note = await create_note(
                 user_id=user_id,
                 title=note_title,