Auto-populate activity log from timer events with edit and delete

- New GET /api/logs/timeline endpoint joins TimerEvent with block/subject/session data
- New PATCH and DELETE /api/logs/timeline/{id} endpoints for editing/removing events
- LogView redesigned as a chronological timeline grouped by date
- Edit inline: timer events support type + time correction; notes support text edit
- Delete works for both auto events and manual notes

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

backend/app/schemas/activity.py

@@ -1,4 +1,4 @@
-from datetime import date
+from datetime import date, datetime
 from pydantic import BaseModel
 
 
@@ -27,3 +27,21 @@ class ActivityLogOut(BaseModel):
     duration_minutes: int | None
 
     model_config = {"from_attributes": True}
+
+
+class TimelineEventUpdate(BaseModel):
+    event_type: str | None = None
+    occurred_at: datetime | None = None
+
+
+class TimelineEventOut(BaseModel):
+    id: int
+    event_type: str
+    occurred_at: datetime
+    session_date: date
+    child_id: int
+    child_name: str
+    block_label: str | None = None
+    subject_name: str | None = None
+    subject_icon: str | None = None
+    subject_color: str | None = None