agents: caller-provided skills hook — repos can ship their own opencode skills

A consuming repo can now add repo-specific skills under .gitea/agent-skills/<name>/
(SKILL.md + skill.json + optional setup.sh); the framework installs the ones
allowed for the running agent. This keeps deploy-target / infra specifics in the
repo they belong to instead of hardcoded in the shared workflow.

- install-caller-skills.sh: scans the caller workspace, installs each skill whose
  skill.json `agents` list includes the running agent, runs its optional setup.sh
  with all inherited secrets available as $SECRETS_JSON (toJSON(secrets) — so a
  caller's setup can read repo-specific secret names the framework can't know),
  and merges the allowed skills into the permission.skill allow-list.
- agent.yml: replace the hardcoded node1-ssh step with the generic caller-skills
  step (passes NAME, WORKSPACE, SECRETS_JSON).
- Remove the built-in node1-ssh skill: delete skill-node1-ssh.sh, drop "node1-ssh"
  from agents.json (senior/lead). The homelab repo now owns that skill.
- run-agent.sh: note caller-provided skills aren't in the roster (route them via
  the caller's AGENTS.md).

toJSON(secrets) verified supported on this Gitea (1.27) via an isolated probe.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/scripts/install-caller-skills.sh

@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# Install CALLER-PROVIDED opencode skills — the framework's skill-plugin hook.
+#
+# The reusable workflow ships a few built-in skills (gitea-api, gitea-admin). A consuming repo can
+# add its OWN, repo-specific skills (e.g. a homelab "ssh into the deploy host" skill) without any
+# change to this framework: it commits them under `.gitea/agent-skills/<name>/` in its own repo.
+# This step discovers them in the checked-out caller workspace and installs the ones allowed for the
+# running agent. That keeps deploy-target / infra specifics in the repo they belong to, not here.
+#
+# Layout the framework expects, per skill, in the CALLER repo:
+#   .gitea/agent-skills/<name>/
+#     SKILL.md     (required) — the opencode Skill doc; copied verbatim into the skill registry.
+#     skill.json   (required) — {"agents":["senior","lead"]} — which agents may load this skill.
+#     setup.sh     (optional) — runtime setup (e.g. write an SSH alias). Runs ONLY when this agent is
+#                  allowed the skill. Receives $SECRETS_JSON (all inherited secrets, as JSON) and must
+#                  extract what it needs via jq; it must no-op cleanly if its secrets aren't set.
+#
+# Required env (provided by the workflow step): NAME WORKSPACE SECRETS_JSON
+#   (SECRETS_JSON = toJSON(secrets); passed so a caller's setup.sh can read repo-specific secrets
+#    whose names this framework cannot know in advance.)
+set -eu
+
+DIR="${WORKSPACE:-$GITHUB_WORKSPACE}/.gitea/agent-skills"
+CFG="$HOME/.config/opencode/opencode.json"
+[ -d "$DIR" ] || { echo "no caller skills (.gitea/agent-skills/ absent) — nothing to install"; exit 0; }
+
+allow='{}'   # skills to flip to "allow" in permission.skill for THIS agent
+for skill_dir in "$DIR"/*/; do
+  [ -d "$skill_dir" ] || continue
+  name=$(basename "$skill_dir")
+  md="$skill_dir/SKILL.md"; meta="$skill_dir/skill.json"
+  if [ ! -f "$md" ] || [ ! -f "$meta" ]; then
+    echo "caller skill '$name': missing SKILL.md or skill.json — skipping"; continue
+  fi
+  # Is this agent allowed the skill?
+  if ! jq -e --arg n "$NAME" '(.agents // []) | index($n)' "$meta" >/dev/null 2>&1; then
+    echo "caller skill '$name': not allowed for @$NAME — skipping"; continue
+  fi
+  # Install the doc.
+  dest="$HOME/.config/opencode/skills/$name"
+  mkdir -p "$dest" && chmod 700 "$dest"
+  cp "$md" "$dest/SKILL.md"
+  chmod -R o=rX "$dest"
+  # Optional runtime setup, with all inherited secrets available as JSON (never printed here).
+  if [ -f "$skill_dir/setup.sh" ]; then
+    echo "caller skill '$name': running setup.sh for @$NAME"
+    SECRETS_JSON="${SECRETS_JSON:-{}}" NAME="$NAME" WORKSPACE="${WORKSPACE:-$GITHUB_WORKSPACE}" \
+      bash "$skill_dir/setup.sh" || { echo "caller skill '$name': setup.sh failed — skipping this skill"; continue; }
+  fi
+  allow=$(jq -nc --argjson a "$allow" --arg n "$name" '$a + {($n):"allow"}')
+  echo "caller skill '$name': installed + allowed for @$NAME"
+done
+
+# Merge the allowed caller skills into the permission allow-list opencode already wrote.
+if [ "$allow" != '{}' ] && [ -f "$CFG" ]; then
+  tmp=$(mktemp)
+  jq --argjson add "$allow" '.permission.skill = ((.permission.skill // {}) + $add)' "$CFG" > "$tmp" && mv "$tmp" "$CFG"
+  echo "permission.skill updated with caller skills: $(jq -c '.permission.skill' "$CFG")"
+fi