Fix malformed date and broken ref shortcodes in docs

[Copilot]

Two documentation build failures: an unparsable ISO 8601 date and Hugo ref shortcodes pointing to non-existent root-level paths.

Changes

• vehicle-update-manager/_index.md — Correct malformed date:

  - date: 2022-072109T14:24:56+05:30
  + date: 2022-07-21T09:14:24+05:30

• develop-seat-adjuster.md — Fix ref shortcodes using absolute paths that don't resolve; the target files exist in the same directory:

  - {{< ref "/deploy-seat-adjuster" >}}
  + {{< ref "deploy-seat-adjuster" >}}
  - {{< ref "/interact-seat-adjuster" >}}
  + {{< ref "interact-seat-adjuster" >}}

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