fix: rename and scope token analyzer to Copilot workflows (#1588)

* fix: add blob storage domain and scope to copilot workflows

- Add *.blob.core.windows.net to network allowed domains so
  gh run download can fetch artifact zips directly via bash
- Scope analysis to Copilot-engine workflows only to stay
  within the 15-minute time budget
- Add time budget guidance and prefer-bash-over-MCP hint

Fixes timeout in run 23875151303 caused by blocked artifact
downloads forcing slow MCP get_job_logs fallback.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: rename token-usage-analyzer to copilot-token-usage-analyzer

Reflects that the workflow is scoped to Copilot-engine workflows
only. Updates description, title-prefix, heading, and recompiles.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lpcox