worktree-agent-isolation

Create a separate git worktree per agent with git worktree add, branching each from origin/main after fetching. Pass each agent the absolute worktree path so their working directories never overlap, then integrate results through GitHub pull requests.

Local main often lags behind after other agents or users merge PRs through the GitHub UI. Fetching first and branching from origin/main ensures all worktrees share the same up-to-date ancestor, reducing rebase conflicts during sequential merges.

The blast_radius_kill_guard.py PreToolUse hook denies unscoped kills like pkill, killall, and shared-cache deletes when two or more agent lanes are live. Re-issuing the exact same command three times opens an escape valve for genuinely needed operations.

The taskpolicy -b background QoS class makes wrapped processes about 2.11x slower, shrinking the margin on fixed startup timeouts. Raise fixed timeouts by at least 2.5x, never wrap long-lived infrastructure like dev servers, or set AI_BADGER_QOS=off to exempt a lane.

Using git worktree add with a remote branch and no -b flag creates a detached HEAD, so commits silently vanish and git push reports everything up-to-date. Always create an explicit local branch with -b or reuse an existing local branch.

Avoid it when tasks must share one worktree deliberately, when tooling like Rider MCP binds only to the main checkout, or when two tasks rewrite the same file — in that case defer the shared section to one owning task instead of duplicating the work.