Closes the remaining minor items tracked under #334 so the issue can be
fully resolved. Each fix is small and targeted.

- #87 is_test_file: path-segment awareness so `latest`, `aspect`,
  `attestation`, `protest` are not mistaken for test files.
- #66 glob_matches: directory excludes (`src/`) match only at segment
  boundaries (`mysrc/`, `docs/src-guide/` no longer caught).
- #68 estimate_tokens: non-empty content returns at least 1 token (was 0
  under integer division).
- #72 RE_JAVA_IMPORT: allow wildcard capture (`import com.example.*` keeps
  the `*`), plus `import static`.
- #73 RE_RUST_MOD: extract `mod foo;` declarations as dependency symbols,
  matching the documented behavior.
- #23 index_stats: query `PRAGMA page_size` instead of assuming 4096 bytes.
- #48 ReviewIssue.issue_type: serialize as `issue_type` (consistent with
  the field name); keep `type` as a deserialize alias.
- #10 Severity::from_str_lossy: use `eq_ignore_ascii_case` (no allocation).

Already-resolved items verified (no change needed):
- #88 max_findings cutoff already sorts severity-descending before truncate.
- #30 debt snapshot save already emits a warn! on write failure.

8 new tests. All 652 tests pass; clippy + fmt + audit clean.

Closes #334