Create or update GitHub PR with gh CLI. Auto-extracts ticket ID from branch name, generates title/summary from commits. Auto-detects existing PR and switches to update mode. Supports --stack for stacked PR chains (per-layer PRs with chained bases; never executes push/rebase). Default: --dry-run (sho
Create or update GitHub PR with gh CLI. Auto-extracts ticket ID from branch name, generates title/summary from commits. Auto-detects existing PR and switches to update mode. Supports --stack for stacked PR chains (per-layer PRs with chained bases; never executes push/rebase). Default: --dry-run (show command, don't execute). Use when: user asks to open/create/update a PR, says /create-pr, wants a