fix(filter)!: resolve only public members

[pdevito3]

For later consideration in a major version. Do not merge now.

Summary

This PR brings back the public-only member lookup that the D1 restore (#155) removed. It is a breaking change, so it needs a major version. The captain decides if and when it merges.

#155 merged into main. This PR is rebased on current main and holds only the break commit. The diff reverts only the member lookup of the D1 restore.

Change

A filter segment matches only a public property or a public field, ignoring case:

• An internal, protected, or private member is an unknown property. The filter throws UnknownFilterPropertyException.
• A query name on a non-public member also throws UnknownFilterPropertyException.
• With AllowUnknownProperties, a clause on a non-public member becomes True == True and does not filter.

This is the main behavior before #155, with one exception. An indexer stays an unknown property, like on current main and v1.14.2. On main before #155, an indexer threw ArgumentException. That error was a fault and not part of the public-only design, so this PR does not bring it back.

Results

Input	v1.14.2 and main	This PR
InternalScore > 30 (internal property)	x.InternalScore > 30	UnknownFilterPropertyException
secretRank == 7 (private field)	x.secretRank == 7	UnknownFilterPropertyException
Owner.InternalAlias == "Ann"	filters	UnknownFilterPropertyException
score > 30, query name on InternalScore	x.InternalScore > 30	UnknownFilterPropertyException
secretRank > 100 with AllowUnknownProperties	x.secretRank > 100	True == True
Item == "x" (indexer)	UnknownFilterPropertyException	UnknownFilterPropertyException

Migration

Make a member public to filter on it.

Tests

• The D1 unit pins in QueryKit.UnitTests/PropertyResolverTests.cs now expect the public-only result. The indexer pins do not change.
• The D1 Postgres pins in QueryKit.IntegrationTests/Tests/PropertyResolverTests.cs now expect UnknownFilterPropertyException for the internal Nickname property, and no filter from the clause with AllowUnknownProperties.
• dotnet test: unit 469 passed, integration 297 passed, 0 failures.
• No README section documents member visibility, so the README does not change.