Address dashboards comment, fix kprobe, mirror to versioned trees

PR #2709 feedback:

- Copilot flagged that the dashboards.mdx description (CE and CC) listed
  "policy" but the page covers Cluster Health / Traffic Volume / DNS /
  Flow / HTTP. Rewrote to match actual page content: "...prebuilt
  dashboards for cluster health, traffic volume, DNS, flow logs, and
  HTTP traffic" (CE) and same with "prebuilt and custom" prefix (CC).
- Vale full sweep across all 7 observability directories surfaced 5
  more line-2 hits on elastic/flow/processpath.mdx (next + 3 versioned
  mirrors) — "kprobe" not in Vale's spelling dictionary. Rewrote as
  "eBPF instrumentation" which covers the same concept without the
  flagged term.

Mirrored next-tree state to versioned snapshots:
- calico_versioned_docs/version-3.32/observability/ (4 files)
- calico-enterprise_versioned_docs/version-3.23-1/observability/ (31)
- calico-enterprise_versioned_docs/version-3.22-2/observability/ (30)
- calico-cloud_versioned_docs/version-22-2/observability/ (27)

Drift notes:
- review-unused-network-policies.mdx exists only in CE next (new
  feature), so no versioned mirrors written for it.
- elastic/policy-activity.mdx exists in CE 3.23-1 but not in CE next
  (removed in next); intentionally untouched.

Vale clean on description lines across all 154 in-scope files; four
content greps clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ctauchen