Fix usage model token breakdown

[AarushiShah-db]

Summary

• Adds per-model token aggregation to the ucode usage SQL query via a model_tokens rollup.
• Updates Top models this week to use actual per-model token totals instead of applying agent/day totals to every model.
• Shows per-model token counts in the daily agent usage table.
• Filters ucode usage output to agents configured by ucode.
• Shows a compact “No usage for in the last 7 days.” message instead of an empty table for configured agents with no recent usage.

Tests

• uv run ruff check .
• uv run ty check src/
• uv run pytest tests/test_lint.py tests/test_usage.py -q
• uv run pytest

Local Test

[AarushiShah-db]

/merge