Track duplicate tracker refactor and compatibility coverage for HGraph/Pyramid

[inabao]

Background

This tracks the duplicate-tracker refactor and follow-up compatibility/testing work now proposed in #1797.

What the PR does

• moves HGraph duplicate tracking from LabelTable into graph-level duplicate trackers
• propagates support_duplicate into graph parameters used by HGraph and Pyramid
• restores legacy HGraph duplicate index compatibility for deserialize and search behavior
• adds deterministic Pyramid duplicate tests for path-aware visibility semantics

Scope notes

• the compatibility fix targets HGraph legacy duplicate indexes
• the new Pyramid work in this PR is test coverage for duplicate semantics, not a Pyramid compatibility fix

PR

• refactor(hgraph): move duplicate tracking to graph layer #1797