Add subject options and redesign TV dashboard layout

Subject options:
- New subject_options table (auto-created on startup)
- SubjectOut now includes options list; all eager-loading chains updated
- Admin: Options panel per subject with add, inline edit, and delete
- WS broadcast and dashboard API include options in block subject data

TV dashboard:
- Three equal columns: Timer | Activities | Schedule
- Activities column shows current subject's options in large readable text
- Activities area has subject-colored border and tinted background
- Subject name and label displayed correctly using embedded subject data

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

backend/app/schemas/subject.py

@@ -1,6 +1,23 @@
 from pydantic import BaseModel
 
 
+class SubjectOptionCreate(BaseModel):
+    text: str
+    order_index: int = 0
+
+
+class SubjectOptionUpdate(BaseModel):
+    text: str | None = None
+
+
+class SubjectOptionOut(BaseModel):
+    id: int
+    text: str
+    order_index: int
+
+    model_config = {"from_attributes": True}
+
+
 class SubjectCreate(BaseModel):
     name: str
     color: str = "#10B981"
@@ -20,5 +37,6 @@ class SubjectOut(BaseModel):
     color: str
     icon: str
     is_active: bool
+    options: list[SubjectOptionOut] = []
 
     model_config = {"from_attributes": True}