[DOCS] Resume Session: show actual dates instead of relative time

Title: /resume needs better metadata — dates, search, favorites

Type: Feature request

What's wrong:
The Resume Session screen shows sessions named by their first message with only relative timestamps ("1 week ago", "2 weeks ago"). This makes it nearly
impossible to find older sessions because:

1. No real dates — "2 weeks ago" could be any of 20 sessions. Show actual dates (e.g., "Mar 22, 14:33")
2. Names are the first message — I never remember what I typed first. Sessions should be named from context/topic, not the opening line
3. No filtering — can't filter by date range, project, or keyword within the session list
4. No favorites/pins — important sessions get buried under newer ones

Suggested improvements:

• Show full date + time instead of relative time
• Auto-generate session names from conversation topic (like how ChatGPT names chats)
• Add date. 1-st April/3-rd April not 4 day ago/1 week ago/2 weeks ago
• Add ability to pin/favorite sessions
• Search should match content inside the session, not just the title

Impact: Medium — makes /resume unusable for power users with many sessions. I have 200+ sessions and finding a specific conversation is a guessing game.