Fix JSON codecs to initialize empty collection properly + bump up coverage limits + remove coverage exclusion for compile-time code

[plokhotnyuk]

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[Copilot]

Pull request overview

Updates JSON binary codec derivation internals (especially record-field handling for default/missing collections) and revises per-module scoverage minimum thresholds in the build.

Changes:

• Refactors record FieldInfo to use an emptyCollectionConstructor (instead of a cached empty instance) and streamlines optional/collection flags.
• Re-tunes coverageMinimumStmtTotal / coverageMinimumBranchTotal for multiple subprojects in build.sbt (and removes some prior per-module coverage exclusions).

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated 1 comment.

File	Description
schema/shared/src/main/scala/zio/blocks/schema/json/JsonBinaryCodecDeriver.scala	Refactors how missing collection fields are defaulted and adjusts field metadata / encoding paths.
build.sbt	Updates per-project scoverage minimums and removes prior macro-source coverage exclusions; also changes benchmark project coverage settings.

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