Remote ordered positions: skip unused physical-count requests

[bedipritpal]

Stage 3: remote ordered-position count traffic, based on upstream fc46dcf after PR187.

• Ordered AdsGetRelKeyPos uses the existing scoped key count and skips the discarded physical-count request.
• Nested position navigation uses the same rule. Natural-order navigation reuses its caller's physical snapshot.
• AdsSetRelKeyPos retains existing physical-count target math, scoped clamping, pending-write flush and index activation. Under today's cache policy, the second natural setter ensure was already a cache hit; no extra setter wire saving is claimed.

Three files (+135/-7), with focused opcode-count regressions and scope doc. No count freshness policy, OPENADS_FRESH_COUNTS, Harbour RDD core, protocol, lock, encryption, security-policy or CI/workflow changes.

Credit/provenance: the three scoped production functions match Pritpal Bedi's released mtfix41 source. New tests/doc are review coverage, not a claim they shipped in that release. Source identity does not establish Vouch's loaded DLL or fresh application validation.

Local Linux GCC11 Debug normal/TLS rebuilt on the PR187 merge. Combined stage2+stage3 focused tests:9cases/208assertions each. Wider normal153cases/93,196assertions and TLS154cases/93,207assertions passed. Counts overlap; warnings-as-errors OFF; slow/flaky/stress patterns excluded. One older external-fixture scope case returns early because its fixture is missing; the new self-contained numeric scope ran. No full CTest, fresh hosted cross-platform gate or Vouch validation claimed.

Negative control on the prior upstream base failed only the three ordered-getter discarded-count assertions; scoped port passed. This measures the actual RPC saving and its limits under current cache policy