@lead: externalize agent.yml inline scripts into .gitea/workflows/scripts/*.sh

Rebased onto the per-agent skill-scoping change so PR #25 carries both:
- route.sh keeps the registry 'skills' allow-list and emits skills as a step output
- install-opencode.sh writes the permission.skill block (deny-all + allow listed)

Pure refactor otherwise: each step's shell moves to its own file, called via
bash "$SCRIPTS/<name>.sh". The two extracted SKILL.md bodies are byte-identical to
main; routing/config/publish behavior is unchanged. Because this is a reusable
workflow (workflow_call) the runtime checkout is the caller's repo, so agent.yml now
checks THIS repo out into .agents-workflow/ (pinned @main) and points $SCRIPTS there.

.gitea/workflows/scripts/fetch-thread.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Fetch the full issue thread (shared memory) into /tmp/thread.md.
+#
+# Required env (provided by the workflow step): GT NUM GITHUB_SERVER_URL GITHUB_REPOSITORY
+set -eu
+
+API="${GITHUB_SERVER_URL}/api/v1/repos/${GITHUB_REPOSITORY}"
+curl -sS -H "Authorization: token $GT" "$API/issues/$NUM/comments?limit=100" 2>/dev/null \
+  | jq -r '.[] |
+      ( if   (.body | test("delegated by"))  then "an automated delegation"
+        elif (.user.login == "ffaerber")     then "ffaerber (the maintainer / you)"
+        else "an AI teammate — the specific one is named in the 🤖 @name line at the top of the comment"
+        end ) as $who |
+      "### comment by \($who):\n\(.body)\n"' > /tmp/thread.md 2>/dev/null || true
+echo "thread comments fetched: $(grep -c '^### comment by ' /tmp/thread.md 2>/dev/null || echo 0)"