[MOD-15396] [SEARCH/AGG] Shard Level Return Strict - Timeout Check up to RPIndex (#9443)

* Intial Commit

* Add scope filtering to StoreResults debug pause mechanism

Extend the StoreResults debug pause API to accept an optional scope parameter (INTERNAL_ONLY or NON_INTERNAL_ONLY) that restricts which requests the global pause applies to. This allows tests to selectively pause only user-facing or only coordinator-dispatched requests, avoiding interference between the two populations. Update all test call sites to specify `internal=False` to maintain existing behavior of pausing only non-internal requests.

* draft tests (to be soft reset)

* Consolidate READ syncpoint and fix can yield partial

* Introduce debug Aggregate Result

* Testing

* Polshies

* Mote Tests + Polish

* Reduce PR footprint

* Fix file

* fix cursors

* Remove total results normalization

* Remove AREQ usage where possible

* Fix macOS build: include <unistd.h> for usleep in debug pause helper

The debug-only debugCheckAndPauseAfterAggregateResult helper added in
aggregate_exec_common.c calls usleep() but does not include <unistd.h>.
On Linux/gcc this builds because unistd.h is pulled in transitively, but
on macOS/clang implicit function declarations are a hard error (since
Xcode 15 / clang 16), failing the merge-queue validation build.