Add "Clear Session" button to reset chat while preserving attached files

[BondSharp]

Describe the need of your request

Currently, when an AI conversation gets confused or goes off-track, the only way to restart is using the "Clear Windows" button. This action removes ALL attached files and workspace context, forcing me to manually re-attach the same project files repeatedly.

This happens multiple times per day when:

• AI misunderstands the context and needs a fresh start
• I want to switch discussion topics within the same project
• The conversation history becomes too cluttered

The current workflow is frustrating and breaks productivity.

Proposed solution

Add a new "Clear Session" button that:

• Clears only the chat history (messages and conversation context)
• Preserves all attached files and workspace context
• Placed next to the existing "Clear Windows" button for clear distinction

This creates a logical separation:

• 🧹 Clear Windows = reset workspace (files + context)
• 🔄 Clear Session = reset conversation only (keep files)

The button should be easily accessible in the same toolbar area as "Clear Windows".

Additional context

User Workflow Example:

1. Working on a project with attached files: Domain.fs, MathHelpers.fs, Stats.fs
2. AI gets confused in conversation about optimization
3. Click "Clear Session" → chat history clears, files remain attached
4. Continue discussion with fresh start, same project context

Why this is different from human conversation:
With humans, I can say "let's start this topic over" verbally. With AI, I need a technical way to reset the conversation without losing the project context.

This feature would significantly improve the developer experience when working with AI assistants on complex projects.

[BondSharp]

Important additional context:

Unlike human communication where I can say "let's start this topic over", with AI I need a TECHNICAL way to reset the conversation.

AI doesn't understand "forget what I said" - it requires an explicit session reset. This makes "Clear Session" a fundamental part of the AI workflow, not just a convenience feature.

The need to reset conversations happens multiple times per hour when:

• AI reasoning goes down the wrong path
• The context window gets cluttered
• I want to try a different approach with the same project files