Add event colors (Catppuccin Mocha) and read-only week view for users

Admins can now pick a color per event from a Catppuccin Mocha palette;
existing events default to blue. Colors flow through to both the admin
timeline and the new "Неделя" tab in the user view, which reuses the
admin's weekly grid in a read-only mode. Also reworks event blocks to
show a single-line "start–end title" so short events no longer overflow,
tidies the admin toolbar, and expands mobile responsiveness across both
frontends.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/database.py

@@ -25,7 +25,7 @@ class Task(Base):
 
 class Event(Base):
     __tablename__ = "events"
-    
+
     id = Column(Integer, primary_key=True, index=True)
     date = Column(String, index=True)  # YYYY-MM-DD
     start_time = Column(String)  # HH:MM
@@ -33,6 +33,7 @@ class Event(Base):
     title = Column(String, nullable=False)
     repeat_weekly = Column(Boolean, default=False)
     weekday = Column(Integer)  # 0=Monday, 6=Sunday, только для weekly events
+    color = Column(String, default="blue")  # ключ цвета из палитры Catppuccin Mocha
 
 
 class WeeklyTaskException(Base):
@@ -58,6 +59,7 @@ class EventException(Base):
     replacement_date = Column(String)
     replacement_start_time = Column(String)
     replacement_duration_min = Column(Integer)
+    replacement_color = Column(String)
 
 
 class TelegramUser(Base):
@@ -85,6 +87,9 @@ async def _run_migrations(conn):
         await conn.execute(text("ALTER TABLE events ADD COLUMN repeat_weekly BOOLEAN DEFAULT 0"))
     if "weekday" not in event_columns:
         await conn.execute(text("ALTER TABLE events ADD COLUMN weekday INTEGER"))
+    if "color" not in event_columns:
+        await conn.execute(text("ALTER TABLE events ADD COLUMN color TEXT DEFAULT 'blue'"))
+        await conn.execute(text("UPDATE events SET color = 'blue' WHERE color IS NULL"))
 
     exception_columns = table_columns.get("weekly_task_exceptions", set())
     if "task_id" not in exception_columns:
@@ -92,6 +97,10 @@ async def _run_migrations(conn):
     if "replacement_date" not in exception_columns:
         await conn.execute(text("ALTER TABLE weekly_task_exceptions ADD COLUMN replacement_date TEXT"))
 
+    event_exception_columns = table_columns.get("event_exceptions", set())
+    if "replacement_color" not in event_exception_columns:
+        await conn.execute(text("ALTER TABLE event_exceptions ADD COLUMN replacement_color TEXT"))
+
 
 async def _get_table_columns(conn):
     table_names = ["tasks", "events", "weekly_task_exceptions", "event_exceptions"]