* CI: add code-size check for files crossing LOC threshold
* feat(ci): add duplicate function detection to CI code-size check
The --compare-to mode now also detects new duplicate function names
introduced by a PR. Uses git diff to scope checks to changed files
only, keeping CI fast.
* fix(ci): address review feedback for code-size check
- Validate git ref upfront; exit 2 if ref doesn't exist
- Distinguish 'file missing at ref' from genuine git errors
- Explicitly fetch base branch ref in CI workflow
- Raise threshold from 700 to 1000 lines
* fix(ci): exclude Swabble, skills, .pi from code analysis
* update gitignore for pycache
* ci: make code-size check informational (no failure on violations)