Add workflow AIC breakdown to repository view

[Copilot]

Repository details expose workflow inventory and registration status but not workflow-level AI Credit allocation.

Changes

• Repository view

  • Adds a pie chart showing the five workflows with the highest measured AIC totals.
  • Places the breakdown alongside existing repository workflow metrics.

• Data model

  • Introduces repository-normalized usage data for route-scoped aggregation.
  • Preserves workflow links for direct navigation from chart entries.

• Coverage

  • Adds unit coverage for usage derivation, repository scoping, and dashboard configuration.

[pelikhan]

@copilot fix https://github.com/githubnext/central-agentic-ops/actions/runs/33556983389/job/100020825514#step:7:1

[Copilot]

@copilot fix https://github.com/githubnext/central-agentic-ops/actions/runs/33556983389/job/100020825514#step:7:1

Fixed in e8001d2 by limiting Playwright to one CI worker, preventing the concurrent browser-session closures behind both shard timeouts. The affected shard and full E2E suite pass locally.