fix: feat: dev-agent merges its own PRs via non-admin Codeberg account (#172)

- phase-handler.sh: remove do_merge(); on APPROVAL inject exact API
  commands for agent to merge+close directly; PHASE:done now only
  does local cleanup (tmux, worktree, labels) — merge already done
- dev-agent.sh: update PHASE_PROTOCOL_INSTRUCTIONS — Approved means
  merge via API, close issue, then write PHASE:done
- dev-poll.sh: remove try_merge_or_rebase(); for approved+CI-green
  orphaned PRs, spawn dev-agent (recovery mode) to merge instead
- .env.example: document new token roles (CODEBERG_TOKEN = bot for
  push/PR/merge; REVIEW_BOT_TOKEN = human account for approvals)
- AGENTS.md: update token descriptions to match new roles

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -9,10 +9,14 @@ PRIMARY_BRANCH=main                        # main or master
 # PROJECT_NAME=yourproject                 # optional — auto-derived from CODEBERG_REPO
 
 # ── Auth tokens ───────────────────────────────────────────────────────────
-# Codeberg API token (read from ~/.netrc by default, override here if needed)
-# CODEBERG_TOKEN=
+# Dev-agent token: push branches, create PRs, merge PRs.
+# Use the dedicated bot account (e.g. factory_bot / disinto_dev).
+# Branch protection: this account must be in the merge whitelist.
+CODEBERG_TOKEN=
 
-# Codeberg review bot token (separate account for formal reviews)
+# Review-agent token: post review comments and submit formal approvals.
+# Use the human/admin account (e.g. johba).
+# Branch protection: this account must be in the approvals whitelist.
 REVIEW_BOT_TOKEN=
 
 # ── Woodpecker CI ─────────────────────────────────────────────────────────