Replace tmux-based run_formula_and_monitor() with synchronous agent_run()
from lib/agent-sdk.sh, matching the pattern established in gardener-run.sh.
Key changes per agent:
- Drop agent-session.sh, use agent-sdk.sh (SID_FILE, LOGFILE)
- Remove SESSION_NAME, PHASE_FILE, PHASE_POLL_INTERVAL (tmux/phase artifacts)
- Create explicit worktree with cleanup trap (replaces formula session worktree)
- Strip phase protocol from prompt footer (SDK mode needs no phase signals)
- Preserve all prompt composition: context blocks, memory, journal, preflight
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>