Remove duplicate folder scanning feature

Delete folder_rename_service.py. Stub out get_duplicate_folders API to return
empty response. Update folder_scan_service and tests to skip rename step.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/server/api/anime.py

@@ -1,6 +1,5 @@
 import logging
 import warnings
-from pathlib import Path
 from typing import Any, List, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, status
@@ -20,9 +19,7 @@ from src.server.exceptions import (
 from src.server.models.anime import AnimeMetadataUpdate
 from src.server.services.anime_service import AnimeService, AnimeServiceError
 from src.server.services.background_loader_service import BackgroundLoaderService
-from src.server.services.scheduler.folder_rename_service import (
-    _scan_for_pre_existing_duplicates,
-)
+
 from src.server.utils.dependencies import (
     get_anime_service,
     get_background_loader_service,
@@ -79,26 +76,14 @@ async def get_anime_status(
 
 
 class DuplicateFolderGroup(BaseModel):
-    """A group of duplicate folders for the same series.
-
-    Attributes:
-        key: Series key (provider-assigned unique identifier)
-        folders: List of folder names that are duplicates
-        folder_count: Number of duplicate folders
-    """
+    """Placeholder - duplicates functionality removed."""
     key: str = Field(..., description="Series key (unique identifier)")
     folders: List[str] = Field(..., description="List of duplicate folder names")
     folder_count: int = Field(..., description="Number of duplicate folders")
 
 
 class DuplicateFoldersResponse(BaseModel):
-    """Response model for duplicate folders listing.
-
-    Attributes:
-        total_groups: Total number of duplicate groups found
-        duplicate_groups: List of duplicate folder groups
-        message: Human-readable summary
-    """
+    """Placeholder - duplicates functionality removed."""
     total_groups: int = Field(..., description="Total number of duplicate groups")
     duplicate_groups: List[DuplicateFolderGroup] = Field(
         ..., description="List of duplicate folder groups"
@@ -112,64 +97,13 @@ async def get_duplicate_folders(
 ) -> DuplicateFoldersResponse:
     """List all pre-existing duplicate folder groups.
 
-    Scans the anime directory for folders with tvshow.nfo files that
-    map to the same series key. Returns groups of duplicates for
-    manual review and cleanup.
-
-    Returns:
-        DuplicateFoldersResponse with groups of duplicate folders
-
-    Note:
-        Not all duplicate folders are safe to merge - some may belong
-        to different releases (e.g., dubbed vs. subbed). Review carefully
-        before taking action.
+    Note: Duplicate folder scanning has been removed. Returns empty response.
     """
-    try:
-        if not settings.anime_directory:
-            return DuplicateFoldersResponse(
-                total_groups=0,
-                duplicate_groups=[],
-                message="Anime directory not configured",
-            )
-
-        anime_dir = Path(settings.anime_directory)
-        if not anime_dir.is_dir():
-            return DuplicateFoldersResponse(
-                total_groups=0,
-                duplicate_groups=[],
-                message=f"Anime directory not found: {anime_dir}",
-            )
-
-        duplicates = _scan_for_pre_existing_duplicates(anime_dir)
-
-        groups = [
-            DuplicateFolderGroup(
-                key=dup.key,
-                folders=dup.folders,
-                folder_count=dup.count,
-            )
-            for dup in duplicates
-        ]
-
-        if groups:
-            message = (
-                f"Found {len(groups)} duplicate group(s). "
-                "Review carefully - some duplicates may be different releases "
-                "(e.g., dubbed vs. subbed)."
-            )
-        else:
-            message = "No duplicate folders found."
-
-        return DuplicateFoldersResponse(
-            total_groups=len(groups),
-            duplicate_groups=groups,
-            message=message,
-        )
-    except Exception as exc:
-        logger.error("Failed to scan for duplicate folders: %s", str(exc))
-        raise ServerError(
-            message=f"Failed to scan for duplicates: {str(exc)}"
-        ) from exc
+    return DuplicateFoldersResponse(
+        total_groups=0,
+        duplicate_groups=[],
+        message="Duplicate folder scanning has been removed.",
+    )
 
 
 class AnimeSummary(BaseModel):