[Epic] Add the built-in Git workspace experience #18

Problem

The operator workbench needs tracked Git features so users can inspect and manage repository state without leaving dotPilot.

Scope

• Track status, diff, staging, commits, history, worktrees, remotes, and timeline views
• Keep Git flows explicit and reviewable

Out of scope

• Implementing provider tool use over Git commands
• Cloud repo management features beyond the desktop operator surface

Planned child issues

• Implement Git status, diff, stage, unstage, and discard flows
• Add commit creation with summaries and local validation hooks
• Build history, compare, and activity timeline views
• Add branch, worktree, and remote operations

Definition of Done

• The Git workspace issues exist and reference this epic
• The epic covers the minimum safe repo-management loop for operator workflows

Verification

• Child issues reference this epic
• The epic remains focused on the in-app Git surface