Merge pull request 'agents: document single-line requirement for caller-skill secrets' (#67) from docs/caller-skills-singleline-secrets into main

toJSON(secrets) leaks multiline secret values (their newlines are escaped, so the
runner's log mask misses them). Note in install-caller-skills.sh that caller-skill
secrets exposed via SECRETS_JSON must be single-line (base64-encode keys/multiline).

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

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

@@ -18,6 +18,12 @@
 # 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.)
+#
+# IMPORTANT — caller-skill secrets read from SECRETS_JSON MUST be single-line. The runner masks a
+# secret's value in logs by exact match, but toJSON(secrets) escapes newlines to '\n', so a MULTILINE
+# secret (e.g. a raw PEM key) no longer matches the mask and would print in cleartext in the step's
+# "expression evaluated to …" log line. Store multiline values base64-encoded (single-line) and
+# decode them inside setup.sh. Single-line values mask correctly.
 set -eu
 
 DIR="${WORKSPACE:-$GITHUB_WORKSPACE}/.gitea/agent-skills"