Add doc-release, contract-compatibility, hook-preflight, hooks-doc-parity,
ci-policy-parity, shellcheck, symlink-rejection, learning-coherence, and
orphan-hooks checks to pre-push-gate.sh (checks 25-33). Add fast-mode
detection for docs/shell/learning file categories so new checks only run
when relevant files change.
Also fix shellcheck warnings in task-validation-gate.sh (SC2053 glob
directives) and remove unused error_msg in watch-codex-stream.sh.