Remove dead projection recursion state

[iuliiasobolevska]

Summary

• remove the unused processedEdges and queryDepth state from client projection generation
• avoid copying the unused edge set for every projectable field
• add direct and mutual cycle coverage pinned to the existing generated projection bytes

The removed state was a cycle/depth guard in the retired v1 generator, but the surviving implementation only copied and forwarded it. Projection generation remains bounded by generatedClasses.

Performance

Three alternating fresh-JVM runs of the exact base (fd6723e3) and PR (e315c9ea) revisions used the same Java 17 CLI configuration and 3.7 MB consumer schema.

Revision	Runs	Median	Range
Base	109.04 s, 130.35 s, 115.60 s	115.60 s	109.04–130.35 s
PR	104.58 s, 105.93 s, 110.13 s	105.93 s	104.58–110.13 s

Median wall time improved by 9.67 seconds, or 8.4%. The base had a wide 21.31-second range, so this is best treated as a directional result for this workload rather than a precise or universal speedup. Both variants generated 9,000 byte-identical files.

Verification

• JAVA_HOME=/Users/isobolevska/.sdkman/candidates/java/17.0.19-zulu ./gradlew :graphql-dgs-codegen-core:formatKotlinMain :graphql-dgs-codegen-core:formatKotlinTest :graphql-dgs-codegen-core:test --no-scan
• generated the 3.7 MB consumer schema before and after the change
• confirmed all 9,000 generated files are byte-identical with diff -rq

[jiholee17]

Asserting the hashed values as strings feels a bit brittle, could maybe consider something like

val projectionNames = codeGenResult.clientProjections.map { it.typeSpec().name() }
        assertThat(projectionNames)
            .containsExactlyInAnyOrder(
                "CycleProjectionRoot",
                "DirectCycleProjection",
                "MutualAProjection",
                "MutualBProjection",
            )

        val projections = codeGenResult.clientProjections.associateBy { it.typeSpec().name() }
        assertThat(projections.getValue("DirectCycleProjection").typeSpec().methodSpecs())
            .extracting("name")
            .contains("name", "self", "mutual")
...