refactor: enforce PLC0415 (import-outside-top-level) for source code

Enable ruff PLC0415 rule for all source files (tests excluded via
per-file-ignores). Move 136 inline imports to top-level across 33 files.
8 imports suppressed with noqa for legitimate reasons: circular
dependencies (client/__init__.py, context.py), optional dependency
guards (app.py document processors, auth/userinfo_routes.py), and
post-env-setup imports (smithery_main.py).

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

nextcloud_mcp_server/client/cookbook.py

@@ -2,6 +2,7 @@
 
 import logging
 from typing import Any, Dict, List
+from urllib.parse import quote
 
 from httpx import Timeout
 
@@ -164,9 +165,6 @@ class CookbookClient(BaseNextcloudClient):
         Returns:
             List of matching recipe stubs
         """
-        # URL encode the query
-        from urllib.parse import quote
-
         encoded_query = quote(query)
         response = await self._make_request(
             "GET", f"/apps/cookbook/api/v1/search/{encoded_query}"
@@ -193,8 +191,6 @@ class CookbookClient(BaseNextcloudClient):
         Returns:
             List of recipe stubs in the category
         """
-        from urllib.parse import quote
-
         encoded_category = quote(category)
         response = await self._make_request(
             "GET", f"/apps/cookbook/api/v1/category/{encoded_category}"
@@ -211,8 +207,6 @@ class CookbookClient(BaseNextcloudClient):
         Returns:
             New category name
         """
-        from urllib.parse import quote
-
         encoded_old_name = quote(old_name)
         response = await self._make_request(
             "PUT",
@@ -241,8 +235,6 @@ class CookbookClient(BaseNextcloudClient):
         Returns:
             List of recipe stubs matching the keywords
         """
-        from urllib.parse import quote
-
         # Join keywords with commas
         keywords_str = ",".join(keywords)
         encoded_keywords = quote(keywords_str)