[FEATURE] Named sessions with /resume <name>

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Currently /resume picks up the most recent conversation. It would be useful to:

1. Name/tag a session (e.g. /save customer-qbr)
2. Resume it later by name (e.g. /resume customer-qbr)

Use case: When working on multiple projects from the same directory, I want to switch between saved sessions without losing context.
Today, starting a new conversation overwrites the /resume target for that directory.

Proposed Solution

i should be able to name sessions as per my naming convention

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_