Prompt-injection hardening from the dataflow analysis in #173 by @Defaultuser361: data-not-instructions rules in /apply and /rank, reviewer research constrained to the user-confirmed company identity, writing-style verify rule tightened to independently located sources (framework_version 1.1.0), SECURITY.md private reporting channel, README note. Closes#173.
* Add framework_version markers to assistant skills and implement CI version guard and update checker
* Address review feedback: update ci.yml based on latest upstream, gate CI version guard to upstream repo, and remove non-ASCII characters from check_upstream_updates.py