[Skills] next-dev-loop: persist login state across loops (#94105)
## Summary
The `next-dev-loop` skill currently asks the user to log in at the start
of every preflight when the target page is gated. With `agent-browser`
0.27.0's `--state <path>` flag and `--session-name <slug>` auto-save,
the saved login can carry from one loop to the next.
This patch updates `skills/next-dev-loop/SKILL.md`:
- **Preflight** — open with `--session-name <slug>` (auto-save on close)
and `--state ~/.agent-browser/sessions/<slug>-default.json` when that
file already exists (omit on first run; a missing path fails the open).
- **Teardown** — note that `--session-name` writes the state on close,
so the next loop's `--state` restores login.
No code changes; doc only.
## Test plan
Verified end-to-end with a headless `claude -p` invocation in a real
logged-in Next.js project:
- The fresh agent reads the updated skill, opens `agent-browser` with
`--session-name <slug> --state <path>`, and finds itself behind the
login — no user input needed.
- After close, the state file's `mtime` advances (auto-save fired).
- Daemon `env` at PID confirms `AGENT_BROWSER_SESSION_NAME` and
`AGENT_BROWSER_STATE` are set correctly.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>