# DEVX-166: Exclude docs/plans/* from PR size check

## Problem
Planning docs in `docs/plans/` are legitimately large (700+ lines) but
fail the PR size check (max 500 lines). This blocks PRs that only add
planning documents.

## Approach
REQ-1: Add `docs/plans/*` to `DEFAULT_EXCLUDED_PATTERNS` in
  `src/devx/ci/check_pr_size.py`
REQ-2: Add test coverage for the new exclusion pattern

## Test Plan
- `make pytest-cov` passes with 100% coverage
- `make lint-all` passes

## Deploy Plan
- Merge to master → post-merge auto-publishes new devx version
- Infra PR #1179 picks up the fix once devx is bumped

## Rollback Plan
- Revert the merge commit

## Acceptance Criteria
- [x] REQ-1: Add `docs/plans/*` to `DEFAULT_EXCLUDED_PATTERNS` in
  `src/devx/ci/check_pr_size.py`
- [x] REQ-2: Add test coverage for the new exclusion pattern