feat(helm): add values comparison for install, upgrade and release detail

[yupanzi]

Summary

Add a values comparison view for Helm install, upgrade, and release detail:

• helm-install-dialog: a new Compare values toggle shows a monaco diff editor instead of the plain editor. On install it compares against the chart's package defaults; on upgrade you can choose the baseline — Deployed values or Package values — with side-by-side / inline and highlight-changes options.
• helmrelease-detail: deployed values can now be viewed and compared across revisions from the release detail page.
• values-diff-editor: shared component wrapping the monaco diff editor (lazy-loaded like the existing editor).
• helm-values: normalization helpers (stable key order, blank-run collapsing) so the diff highlights real changes instead of formatting noise — unit-tested.
• chart version sorting: versions are now ordered by semver with publish time only as a tie-breaker, so the upgrade dropdown is correct for repackaged/backported indexes (previously publish time won, which could put an older version on top).
• e2e: the helm spec now covers the comparison flow; window.monaco is exposed so tests can drive the editors, matching what the AMD build already did.
• New yaml runtime dependency for values normalization.

Why

When installing or upgrading a chart it is easy to lose track of what actually changed in the values, especially on upgrades where the edited values drift from both the chart defaults and what is currently deployed. Kubeapps solves this with a values diff view; this PR brings the same idea to Kite.

Related issue

Closes #667

Validation

• go test ./pkg/helm/... (new content_test.go covers the version ordering)
• pnpm run type-check && pnpm run lint && pnpm run test (new helm-values.test.ts)
• make e2e-run SPEC=specs/helm-kite.spec.ts flow extended for the diff view

Checklist

• I reviewed this PR myself before requesting review.
• I understand the changes, including AI-generated parts (if any).
• For new features, a feature request issue is linked.
• I cleaned up AI noise (unnecessary comments, dead code, and unrelated changes).
• This PR is reasonably scoped (or split into smaller PRs).

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