Build Session Workflow & Prompts configuration tab

[itdove]

Description

Create tab for session workflow and prompts configuration.

Tasks

• Create SessionWorkflowTab component
• Add tri-state switches (Always/Never/Prompt)
• Implement prompts config fields
• Add AI agent backend selection
• Add auto-launch Claude toggle
• Add auto-commit/PR toggles
• Display current settings clearly
• Handle state updates

Acceptance Criteria

• All prompt settings are editable
• Tri-state switches work correctly
• Agent backend dropdown shows valid options
• Auto-launch/auto-commit toggles work
• Settings descriptions are clear
• Changes update parent state
• Form follows PatternFly patterns

Estimated Effort: 3-5 days

[itdove]

Child of #305