feat: restore CI/release, prompt contracts, faster install (0.9.33)

Bring back Gitea CI + auto-publish; share release helpers; strengthen multi-turn
tool/job prompts with a unit contract; ccache/make help and --release bootstrap.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/release.sh

@@ -12,6 +12,8 @@
 # check is skipped under GITEA_ACTIONS / GITHUB_ACTIONS / CI.
 set -euo pipefail
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+# shellcheck source=lib_release.sh
+. "$ROOT/scripts/lib_release.sh"
 SERVER="${CST_GITEA:-${GITHUB_SERVER_URL:-https://git.whcself.xyz}}"
 REPO="${CST_REPO:-${GITHUB_REPOSITORY:-WHC/CST-agent}}"
 API="$SERVER/api/v1/repos/$REPO"
@@ -33,7 +35,7 @@ for f in "$@"; do
 done
 cd "$ROOT"
 
-ver="$(sed -n 's/^#define CST_VERSION_\(MAJOR\|MINOR\|PATCH\) \([0-9]*\)$/\2/p' include/cst_version.h | paste -sd.)"
+ver="$(cst_version)"
 tag="v$ver"
 
 # If this job was triggered by a version tag, it must match cst_version.h.