fix: chore(26a): delete action-agent.sh, action-poll.sh, and action/AGENTS.md (#65)

- Delete action/ directory and all its contents
- Remove action-bot from bin/disinto bot token mapping and collaborator lists
- Remove FORGE_ACTION_TOKEN from lib/env.sh and .env.example
- Remove action-bot from FORGE_BOT_USERNAMES in lib/env.sh and .env.example
- Update .woodpecker/agent-smoke.sh to remove action script checks
- Update AGENTS.md: remove action agent from description and table
- Update lib/AGENTS.md: remove action-agent references from sourced by columns
- Update docs/PHASE-PROTOCOL.md: remove action-agent reference
- Update docs/AGENT-DESIGN.md: remove action-agent from agent table
- Update planner/AGENTS.md: update action formula execution reference
- Update README.md: update formula-driven execution reference

Part of #26 — retire action-agent system.

.woodpecker/agent-smoke.sh

@@ -214,8 +214,6 @@ check_script vault/vault-agent.sh
 check_script vault/vault-fire.sh
 check_script vault/vault-poll.sh
 check_script vault/vault-reject.sh
-check_script action/action-poll.sh
-check_script action/action-agent.sh
 check_script supervisor/supervisor-run.sh
 check_script supervisor/preflight.sh
 check_script predictor/predictor-run.sh