v0.8.10 — Git worktrees for agentic sessions

Added

• Git worktrees for agentic sessions (full product surface)
  • New session: worktree toggle (on by default) + optional branch name
  • Session list wt badge when isolated
  • Projects: Worktree quick-start action
  • Git page: worktrees panel + start session from a linked worktree
  • API: GET /v1/git/worktrees?cwd=

Worktrees land under .agents/worktrees/<id> with branch agents/<id> (or custom).
Session delete best-effort removes the worktree.

Full Changelog: v0.8.9...v0.8.10