Add more metadata to agent upgrade telemetry (#99925)
### Why?
Upgrade outcomes lack version and runtime context, so failures and
missing results cannot be compared by upgrade path or environment.
### How?
Add metadata to the existing run-linked events:
- Run start: the app's starting Next.js version, the invoking CLI's Node
version, and the package manager and its version when available.
- CLI result: the starting and approved target Next.js versions.
- Agent result: the installed app Next.js version when the result is
reported.
Keep existing run IDs, agent detection/selection, and policy attribution
so analyses can group outcomes by version path, Node version, agent,
policy, and package manager.
Reuse the upgrade commands' package-manager selection. Version lookup
failures warn and leave metadata null without stopping the upgrade.
Targets are recorded only after preparation succeeds; copied or printed
prompts may have no identified agent. Analyses should retain unknown
metadata in their denominators.
The receiver and compression schemas must be updated and deployed to
retain the new fields. Historical events cannot gain metadata they never
recorded.
Full CLI execution verification is blocked by missing workspace
dependencies and build outputs.
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