fix: merge session-only model analytics rows

[teknium1]

Summary

Models analytics now folds unaccounted session-only rows into the matching accounted provider row, so direct-provider OpenRouter usage does not render as a duplicate zero-token model card.

Changes

• /api/analytics/models: merge zero-usage, no-provider rows into the sole accounted provider row for the same model when unambiguous.
• Tests: cover the DeepSeek/OpenRouter duplicate-card shape with one session-only row plus one accounted row.

Validation

Check	Result
python3 -m py_compile hermes_cli/web_server.py tests/hermes_cli/test_web_server.py	pass via /home/teknium/.hermes/hermes-agent/.venv/bin/python
pytest tests/hermes_cli/test_web_server.py -q -k 'models_analytics_merges_session_only_duplicate or analytics_usage'	3 passed, 271 deselected

Note: the worktree has no local .venv; verification used the main checkout venv at /home/teknium/.hermes/hermes-agent/.venv/bin/python, which has the dashboard deps installed.

Infographic

[github-actions]

🔎 Lint report: hermes/hermes-c6397904 vs origin/main

ruff

Total: 0 on HEAD, 0 on base (➖ 0)

🆕 New issues: none

✅ Fixed issues: none

Unchanged: 0 pre-existing issues carried over.

ty (type checker)

Total: 10889 on HEAD, 10889 on base (➖ 0)

🆕 New issues: none

✅ Fixed issues: none

Unchanged: 5711 pre-existing issues carried over.

Diagnostics are surfaced as warnings — this check never fails the build.