Fix vault-ocr executable path to AGENT_ENGINE_ROOT

[matteopasseri407]

What this changes and why

How it was tested

Checklist

• Ran the regression suite locally (python3 -m pytest from
  03-INFRA/agent-universal-layer/tests/) and it's green
• If this touches a shell script or a PowerShell script: both OS
  dialects are covered, or there's an explicit reason one doesn't apply
• If this touches generated CLI config: I edited the generator
  (render.py / agent_sync.py / skills-sync.py), not a generated
  output file by hand
• If this changes the architecture (a component, a flow, a structural
  rule): 03-INFRA/agentic-layer-concept-map.md is updated in the same
  PR
• No secrets, tokens, real IPs, or personal paths in the diff (CI's
  leak-scan will catch most of this, but it's not a substitute for
  checking)

[matteopasseri407]

Superseded: this exact change is already on main as 42bf515, with the same title. git diff origin/main <branch> -- 03-INFRA/agent-universal-layer/mcp/manifest.yaml is empty — there is no content left to merge.

The branch is 29 commits behind main (it predates v0.94.0 through v0.96.0), so merging it now would only add a merge commit and a conflict surface for a change that already landed. Closing rather than rebasing.

Only leftover: the env: mapping under windows: picked up a stray blank line in that commit. Harmless to YAML, and it will be tidied with the next change that touches the manifest.