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/models/subject.py

@@ -1,4 +1,4 @@
-from sqlalchemy import String, Boolean, ForeignKey
+from sqlalchemy import String, Boolean, ForeignKey, Text, Integer
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from app.models.base import Base, TimestampMixin
 
@@ -20,3 +20,20 @@ class Subject(TimestampMixin, Base):
     activity_logs: Mapped[list["ActivityLog"]] = relationship(  # noqa: F821
         "ActivityLog", back_populates="subject"
     )
+    options: Mapped[list["SubjectOption"]] = relationship(
+        "SubjectOption", back_populates="subject", cascade="all, delete-orphan",
+        order_by="SubjectOption.order_index"
+    )
+
+
+class SubjectOption(Base):
+    __tablename__ = "subject_options"
+
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    subject_id: Mapped[int] = mapped_column(
+        ForeignKey("subjects.id", ondelete="CASCADE"), nullable=False
+    )
+    text: Mapped[str] = mapped_column(Text, nullable=False)
+    order_index: Mapped[int] = mapped_column(Integer, default=0)
+
+    subject: Mapped["Subject"] = relationship("Subject", back_populates="options")