spec-spine: Hook for Claude Code

{
  "Stop": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "cd \"${CLAUDE_PROJECT_DIR:-.}\" 2>/dev/null || exit 0\n[ -d specs ] || exit 0\n# Resolve the spec-spine binary for the repository this hook acts on:\n# $SPEC_SPINE_BIN, then that repository's own release build, then PATH. A repo\n# that builds its own binary must be governed by the one it builds; the PATH\n# fallback keeps an adopter on the published CLI working (spec 051).\nspec_spine_bin() {\n  if [ -n \"${SPEC_SPINE_BIN:-}\" ] && [ -x \"${SPEC_SPINE_BIN}\" ]; then echo \"${SPEC_SPINE_BIN}\"; return 0; fi\n  if [ -x \"$1/target/release/spec-spine\" ]; then echo \"$1/target/release/spec-spine\"; return 0; fi\n  command -v spec-spine 2>/dev/null\n}\nsc=$(spec_spine_bin \"${CLAUDE_PROJECT_DIR:-.}\") || sc=''\n[ -n \"$sc\" ] || { echo '[codebase-index] spec-spine absent, staleness check skipped (run /setup)'; exit 0; }\n# Read-only by design. A session that has ended cannot commit a regenerated\n# index, so writing one here leaves .derived/ dirty; an orchestrator that\n# refuses to start a session on a dirty tree then never starts one, and the\n# pipeline stalls on dirt it produced itself.\n\"$sc\" index check >/dev/null 2>&1 && exit 0\necho '[codebase-index] STALE: run `spec-spine index` and commit the regenerated shards with the change that made them stale.'\necho '[codebase-index] Not regenerated here: a write at session end leaves .derived/ uncommitted, and the next run refuses a dirty tree.'\ntrue"
        }
      ]
    }
  ]
}