Align dashboard with the route dimension introduced in the previous
commit:
* Token Usage / API Requests pie charts query the breakdown API with
`group_by: ['date', 'route']` and aggregate via the new `route`
dimension in `buildUsageLabel`. Visible chart titles keep the existing
"by Model" wording — only the underlying data dim changed.
* Overview "Models" card label switched to `dashboard.deployments`
("部署" / "Deployments"), and the Active Models table heading to
`dashboard.activeDeployments`. These reflect the underlying entity
(model deployments) more accurately now that routes are the
user-facing model concept.
* Drop 11 unused dashboard locale keys (`dashboard.title`,
`dashboard.models`, `dashboard.allocategpus`, `dashboard.instances`,
`dashboard.disk`, `dashboard.diskutilization`, `dashboard.apirequest`,
`dashboard.activeModels`, `dashboard.activeUsers`,
`dashboard.activeModels.name`, `dashboard.runninginstances`) — no
remaining references in `src/` after the rename. Locale parity check
passes.
