Parametr select u vypisu, telo udalosti v calendarView

- calendar/view: include_body a body_type (html, text), telo udalosti
  rovnou ve vypisu bez dalsiho volani
- select u vypisu mailu, udalosti, calendarView, jedne udalosti a skupin;
  nahrazuje vychozi sadu poli
- app/graph_fields.py: vychozi sady a seznamy dostupnych poli, Swagger
  je zobrazuje v popisu parametru
- README: endpointy, popis select, zaznam zmen

app/services.py

@@ -6,6 +6,7 @@ from urllib.parse import quote
 from fastapi import HTTPException, status
 
 from .graph_client import MicrosoftGraphClient
+from .graph_fields import EVENT_DEFAULT_SELECT, GROUP_DEFAULT_SELECT, MESSAGE_DEFAULT_SELECT
 from .schemas import (
     CalendarEventRequest,
     CalendarEventUpdateRequest,
@@ -45,11 +46,13 @@ class MailService:
     def __init__(self, graph: MicrosoftGraphClient) -> None:
         self._graph = graph
 
-    async def list_messages(self, user_id: str, folder: str = "Inbox", top: int = 25) -> Any:
+    async def list_messages(
+        self, user_id: str, folder: str = "Inbox", top: int = 25, select: str | None = None
+    ) -> Any:
         params = {
             "$top": top,
             "$orderby": "receivedDateTime desc",
-            "$select": "id,subject,from,toRecipients,receivedDateTime,hasAttachments,isRead,webLink",
+            "$select": select or MESSAGE_DEFAULT_SELECT,
         }
         return await self._graph.request(
             "GET",
@@ -82,9 +85,12 @@ class MailService:
         )
 
 
-CALENDAR_EVENT_SELECT = (
-    "id,subject,start,end,location,attendees,webLink,isOnlineMeeting,onlineMeeting,showAs,isCancelled,organizer"
-)
+def _with_body(select: str) -> str:
+    fields = [f.strip() for f in select.split(",") if f.strip()]
+    for extra in ("body", "bodyPreview"):
+        if extra not in fields:
+            fields.append(extra)
+    return ",".join(fields)
 
 
 class CalendarService:
@@ -95,11 +101,11 @@ class CalendarService:
         """Default calendar of the mailbox (id, name, owner). Cheapest read-only access check."""
         return await self._graph.request("GET", f"/users/{graph_segment(user_id)}/calendar")
 
-    async def list_events(self, user_id: str, top: int = 25) -> Any:
+    async def list_events(self, user_id: str, top: int = 25, select: str | None = None) -> Any:
         params = {
             "$top": top,
             "$orderby": "start/dateTime",
-            "$select": CALENDAR_EVENT_SELECT,
+            "$select": select or EVENT_DEFAULT_SELECT,
         }
         return await self._graph.request("GET", f"/users/{graph_segment(user_id)}/events", params=params)
 
@@ -110,15 +116,24 @@ class CalendarService:
         end: str,
         top: int = 25,
         time_zone: str | None = None,
+        include_body: bool = False,
+        body_type: str = "html",
+        select: str | None = None,
     ) -> Any:
+        fields = select or EVENT_DEFAULT_SELECT
         params = {
             "startDateTime": start,
             "endDateTime": end,
             "$top": top,
             "$orderby": "start/dateTime",
-            "$select": CALENDAR_EVENT_SELECT,
+            "$select": _with_body(fields) if include_body else fields,
         }
-        headers = {"Prefer": f'outlook.timezone="{time_zone}"'} if time_zone else None
+        prefer: list[str] = []
+        if time_zone:
+            prefer.append(f'outlook.timezone="{time_zone}"')
+        if include_body:
+            prefer.append(f'outlook.body-content-type="{body_type}"')
+        headers = {"Prefer": ", ".join(prefer)} if prefer else None
         return await self._graph.request(
             "GET",
             f"/users/{graph_segment(user_id)}/calendarView",
@@ -133,11 +148,11 @@ class CalendarService:
             json=request.as_graph_payload(),
         )
 
-    async def get_event(self, user_id: str, event_id: str) -> Any:
+    async def get_event(self, user_id: str, event_id: str, select: str | None = None) -> Any:
         return await self._graph.request(
             "GET",
             f"/users/{graph_segment(user_id)}/events/{graph_segment(event_id)}",
-            params={"$select": CALENDAR_EVENT_SELECT + ",body"},
+            params={"$select": select or _with_body(EVENT_DEFAULT_SELECT)},
         )
 
     async def update_event(self, user_id: str, event_id: str, request: CalendarEventUpdateRequest) -> Any:
@@ -264,8 +279,8 @@ class GroupsService:
     def __init__(self, graph: MicrosoftGraphClient) -> None:
         self._graph = graph
 
-    async def list_groups(self, top: int = 25) -> Any:
-        params = {"$top": top, "$select": "id,displayName,mail,groupTypes,securityEnabled,mailEnabled"}
+    async def list_groups(self, top: int = 25, select: str | None = None) -> Any:
+        params = {"$top": top, "$select": select or GROUP_DEFAULT_SELECT}
         return await self._graph.request("GET", "/groups", params=params)
 
     async def list_team_channels(self, team_id: str) -> Any: