test: add comprehensive viz dashboard test suite

38 tests covering:
- Shell script syntax validation (3)
- Python module syntax validation (5)
- Parser functionality: parse_session, canonical rounds, goal tracker,
  Completed and Verified parsing, list_sessions, is_valid_session,
  malformed session skip (6)
- Analyzer: empty sessions, basic statistics, verdict distribution
  excludes non-reviewed rounds (3)
- Exporter: Markdown generation, bilingual {zh,en} dict handling (2)
- Integration markers: VIZ_AVAILABLE/VIZ_PROJECT in setup script,
  viz-stop in cancel script, viz prompt in start command (5)
- Command & skill definitions (3)
- Static asset existence + i18n English-only check + requirements (11)

Signed-off-by: Chao Liu <chao.liu.zevorn@gmail.com>

Author: zevorn