Add a Filter Icon for Date-Based Chat Searching

Users with long chat histories struggle to track down older conversations and have requested ways to search or filter by date. While adding timestamps to every chat title would clutter the clean UI, requiring users to type complex search commands (like date:2023) is too advanced and hidden for the average user.

The Proposed Solution:
Add a small "Filter" icon (like a funnel) directly next to or inside the "Search your threads..." bar. Clicking this icon would open a small, simple dropdown menu allowing users to visually select a timeframe.

• This dropdown could include quick options like "This Month", "Last 3 Months", or a simple calendar/date-range selector.

• Once selected, the sidebar only displays chats active during that period.

The Benefit:
This provides an incredibly intuitive, point-and-click way for average users to filter their chat history. It completely solves their frustration of losing older chats, makes the feature highly visible, and perfectly preserves the minimalist design of the chat list itself.