Fix broken internal links in the openvoxdb collection

[miharp]

Problem

The openvoxdb collection has broken internal links. Companion to #262 (openvox collection); filed so the collection can reach zero before CI link checking is enabled for it.

Measured against a complete local build (all references generated) with:

htmlproofer _site/openvoxdb/latest --root-dir _site \
  --disable-external --no-enforce-https --ignore-empty-alt --checks Links

Excluding the 9 OpenBolt sidebar pages from #202, there are ~11 distinct broken targets:

Missing pages / stale paths

• /puppetdb/3.2/migrate.html (legacy puppetdb path — should point within /openvoxdb/latest/)
• ../dev-docs/local-dev.md and ./CONTRIBUTING.md#running-the-tests (links to repo dev docs, not published)
• configure-postgres, migration-coordination (bare slugs missing .html/path)

Anchor drift (file exists, fragment does not)

• ./configure.html#using-postgresql
• ./puppetdb_connection.html#serverurls
• ./ast.html#paging-operators-limit-offset-orderby, ./v4/ast.html#selectentity-subquery-statements, ../../../api/query/v4/ast.html#regexp-array-match
• /openvox/latest/lang_facts_and_builtin_vars.html#puppet-master-variables

The 9 #202 OpenBolt sidebar pages are out of scope (resolve once #202 lands).