ci: measure coverage, and drop tests other tests already cover (#13)

* ci: measure test coverage of the hooks

claude plugin test measures no coverage, and the hooks run in the
engine's own environment, where no coverage tool sees them. So
npm run coverage instruments a copy of the plugin with istanbul,
has each test read the counts back through a __coverage command when it
ends, and reports them as text and lcov. CI prints the table in the
job summary.

* test: drop the tests other tests already cover

Coverage per test showed 11 tests whose lines the rest run too: the
pane listing per surface, the session press, the full replay, the
kept-token and CLAUDE_CONFIG_DIR connects, /leverage with no token,
the subagent step, the network retry and logout. Line coverage goes
from 62.18% to 61.69%.

The token-safety tests stay though others run their lines: they are
the only ones that check a token is never kept where others can read
it.

* ci: comment the coverage table on each PR

One comment per PR, edited on each push. Skipped for forks, whose
token cannot comment.

Author: aripiprazole

.github/workflows/ci.yml

@@ -6,6 +6,7 @@ on:
 
 permissions:
   contents: read
+  pull-requests: write
 
 concurrency:
   group: ci-${{ github.ref }}
@@ -23,3 +24,15 @@ jobs:
       - run: npm install -g @anthropic-ai/claude-code@2.1.286
       - run: claude plugin validate .
       - run: claude plugin test .
+      - run: npm ci
+      - name: Coverage
+        run: |
+          { echo '### Coverage'; echo '```'; npm run -s coverage; echo '```'; } |
+            tee "$RUNNER_TEMP/coverage.md"
+          cat "$RUNNER_TEMP/coverage.md" >> "$GITHUB_STEP_SUMMARY"
+      # One comment per PR, updated on each push. A fork's token cannot comment.
+      - name: Comment coverage on the PR
+        if: github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: gh pr comment ${{ github.event.pull_request.number }} --body-file "$RUNNER_TEMP/coverage.md" --edit-last --create-if-none

.gitignore

@@ -2,3 +2,4 @@ node_modules/
 .DS_Store
 *.log
 .claude/
+coverage/