feat: add total buckets tracking

[joshuabrink]

Enhances the Sync Diagnostics page by making the server-side parameter query result limit more visible to users and providing clearer warnings as the bucket count approaches this limit.

[changeset-bot]

🦋 Changeset detected

Latest commit: 5bb7870

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

This PR includes changesets to release 1 package

Name	Type
@powersync/diagnostics-app	Patch

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]

I think it's great to track & report this, but should be clear on the wording.

Note that there are actually two separate limits, both with a default of 1000, and both reported with code PSYNC_S2305:

1. "Too many buckets". This is what the PR here measures.
2. "Too many parameter query results".

These are often the same, but is different in some important cases:

1. If the parameter query or sync stream subquery has duplicate results, those are counted individually for "parameter query results", but de-duplicated in the bucket count.
2. Queries that don't result in partitioning don't count towards "parameter query results", but do count 1 towards the number of buckets.

Another point is that the limit of 1000 is the default. While it's not common to change this, the text here shouldn't present that as always the case.