[Postgres] Skip redundant current_data copies for REPLICA IDENTITY FULL

[joshuabrink]

Re-implements #459 (which resolves #398)

Tables with REPLICA IDENTITY FULL always send the complete row on every change, so PowerSync's per-row copy in current_data is redundant for them. This makes store_current_data a per-table flag rather than a global one, skipping the copy (and the TOAST-merge read) for FULL tables while keeping it for every other replica identity.

What changed

The source reports a source-agnostic sendsCompleteRows on the entity descriptor (true only for FULL in Postgres), and resolveStoreCurrentData in service-core derives the stored flag from it: reported true = no copy, reported false = keep a copy, unreported = preserve the persisted value. Keeping the resolution in core means the storage backends don't each re-derive the three-state logic.

The flag is resolved during table resolution and re-evaluated on every pgoutput Relation message, so a mid-stream ALTER TABLE ... REPLICA IDENTITY is picked up without a re-snapshot. Reverting FULL to DEFAULT correctly falls back to a targeted resnapshot for any row that can no longer be completed from storage.

Compatibility

Backward compatible, the column defaults to NULL (treated as true), and existing FULL tables pick up the optimization on their next DML or ALTER. No re-snapshot required on upgrade.

Testing

E2E tests in module-postgres cover both ALTER directions (including TOAST recovery), and module-mongodb-storage covers the storage-layer flag for v1 and v3.

AI Usage

This PR was AI-assisted (Claude Code), manually directed, reviewed, and tested.

[changeset-bot]

🦋 Changeset detected

Latest commit: 65ca4e7

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 11 packages

Name	Type
@powersync/service-core	Minor
@powersync/service-module-mongodb-storage	Minor
@powersync/service-module-postgres-storage	Minor
@powersync/service-module-postgres	Minor
@powersync/service-module-core	Patch
@powersync/service-module-mongodb	Patch
@powersync/service-module-mssql	Patch
@powersync/service-module-mysql	Patch
@powersync/service-image	Minor
test-client	Patch
@powersync/service-schema	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[rkistner]

Before I did too far into the details - is there a way to do this that would avoid persisting the store_current_data flag on the SourceTable?

If that's not feasible, we should look into a more generic way of storing db-specific metadata on the SourceTable - I know we have another similar requirement for persisting MSSQL change capture instances - cc @Rentacookie.