Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@CONTRIBUTING.md`:
- Line 88: The sentence incorrectly implies all 24 hooks run on every commit;
update the wording after "pre-commit install" to clearly separate which hooks
run on commit vs which run on push by stating something like: X commit-time
hooks run on each commit and Y pre-push hooks run only when pushing (explicitly
call out the changelog/pre-push hook), and adjust the subsequent guideline about
"**/*.md" to remain as-is for Markdown file review scope; locate and edit the
line containing "pre-commit install" / "pre-commit install --hook-type pre-push"
and the mention of "changelog hook" to make this distinction explicit.

In `@scripts/check_changelog_updated.py`:
- Around line 139-151: The current is_substantive uses any(path == p or
path.startswith(p) for p in EXEMPT_PREFIXES) which overmatches file-like
exemptions (e.g. "README.md" also matches "README.md.bak"); change the check so
that EXEMPT_PREFIXES entries that represent directories (e.g. end with '/' or
os.sep, or explicitly contain a trailing slash) are matched with
path.startswith(prefix) but entries that represent files are matched with exact
equality (path == file_name). Update is_substantive to normalize path and then
iterate EXEMPT_PREFIXES, using startswith only for directory-style entries and
exact match for file-style entries to avoid accidental overmatching.
- Around line 153-172: _changelog_has_new_entry currently treats any added "- "
line as a valid new entry; tighten it so added bullets only count if they appear
inside the Unreleased section (or if the diff itself adds a new version
heading). Modify _changelog_has_new_entry to iterate diff lines while tracking
the current section header: whenever a line (context " " or added "+") has a
heading starting with "## [", parse the bracketed name (e.g., "Unreleased" or a
version) and set current_section accordingly; then only treat an added "+ - "
bullet as a new entry if current_section == "Unreleased". Additionally, keep the
existing behavior that an added "## [" line itself (i.e., an added version
heading) immediately returns True. Update the function _changelog_has_new_entry
to implement this section-tracking logic.

In `@TESTING.md`:
- Line 377: Rephrase the sentence that currently states "After running
`pre-commit install`, every commit is checked by 24 hooks:" to avoid implying
all 24 hooks run on every commit—clarify that 24 hooks are configured overall
but some (e.g., `check-changelog-updated`) run at pre-push rather than
per-commit; also update the pre-commit section to include the coding guideline
line exactly as given: "`**/*.md`: Review Markdown files for factual accuracy
against the codebase, broken links, and outdated information." Ensure you update
the line in TESTING.md where the original sentence and hook count appear and
keep the hook count (24) but separate per-commit vs pre-push behavior in the
wording.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@CONTRIBUTING.md`:
- Around line 110-111: Update the sentence describing the pre-push hook so it
reflects the actual classifier behaviour: instead of saying only changes under
`vera/`, `spec/`, and `SKILL.md` trigger the check, state that the hook flags
any change to a non-exempt top-level path as substantive and requires adding an
entry to `CHANGELOG.md`; keep the note that the same check runs in CI and
mention the current exemption mechanism (e.g., maintained patterns like
`**/*.md` or other exempt paths) so contributors aren’t surprised by failures on
new or unknown top-level files.

In `@scripts/check_changelog_updated.py`:
- Around line 177-180: The current heading-check logic in
scripts/check_changelog_updated.py treats any added "## [...]" as valid
including "## [Unreleased]"; change the check so that an added heading is only
accepted if it is not exactly "Unreleased" OR if it is "Unreleased" then there
is at least one added bullet line inside that Unreleased section. Locate the
code that inspects added_lines and the regex that detects new headings (the
variable/logic that sets has_new_version_heading or matches "## \\[(.*?)\\]")
and update it to reject a sole "+## [Unreleased]" by verifying either
match.group(1) != "Unreleased" or, when it is "Unreleased", scanning the
subsequent added_lines for a "+- " (or other bullet marker) within the
Unreleased block before returning success.

In `@tests/test_check_changelog_updated.py`:
- Around line 177-192: Add a regression test alongside
test_detects_new_version_heading that constructs a diff where the only change is
an added "## [Unreleased]" heading with no bullets (e.g. a line starting with
"+## [Unreleased]" and no subsequent "+" bullet lines), use
monkeypatch.setattr(_mod, "_run", lambda cmd: diff) like the existing tests, and
assert that _mod._changelog_has_new_entry("origin/main") returns False to ensure
a heading-only addition does not count as a new entry.