fix(plugins): offer Parquet in Export until the manifest lists it

[datlechin]

Why

#3503 builds the Export dialog's install offers from exportFormatIds in v3.json, but scripts/release/registry.py never writes that field. Once 0.82.0 ships, a user without the Parquet plugin gets no Install Parquet… in the format menu, which the docs still describe.

Change

• Install Parquet… is offered again while the manifest names no export format.
• A format the manifest lists replaces the hand entry, so a later registry.py change takes over with no duplicate.

Verified

ExportFormatCatalogTests: parquetOfferedWithoutManifestFormats fails on main and passes here. installableComesFromTheManifest pinned the empty offer list on purpose and is replaced by the two new cases.

Not in this PR

• registry.py writing exportFormatIds from TableProProvidesExportFormatIds; the hand Parquet entry goes with it.
• The docs field table drops exportFormatIds in TableProApp/docs (paired PR).