refactor: sketch-core retirement + branch-pin cleanup + elastic DSL test fix (#309)

* Revert "Revert "refactor: retire sketch-core mirror (#307)" (#310)"

This reverts commit ea723f4.

* chore: track asap_sketchlib main + fix elastic DSL quantile assert

After PR #307 was admin-merged with a failing test (and then reverted in
PR #310), redo the consumer migration cleanly with two follow-up changes:

1. Drop the \`branch = "refactor/adopt-sketch-core-modules"\` pin from
   asap-query-engine/Cargo.toml. asap_sketchlib#36 is on main as
   commit \`d22a9ab\`; the consumer now tracks the default branch.

2. Loosen the \`test_esdsl_time_range_query\` assertion to ±1 tolerance.
   The test computed P90 of 200..300 from a KLL and asserted exactly 291;
   asap_sketchlib's KLL reports 290 on this distribution, which is within
   KLL's published rank-error bound but breaks an exact-match assertion
   that previously passed against the dsrs/datasketches backend (now
   retired with sketch-core).

Tests:
- \`cargo test -p query_engine_rust --lib precompute_operators\` → 87 / 0
- \`cargo test -p query_engine_rust --lib tests::elastic\` → 15 / 0
- \`cargo test -p query_engine_rust --lib tests::elastic_dsl_query_tests::tests::test_esdsl_time_range_query\` → passes

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: zzylol

Cargo.lock

@@ -1,7 +1,6 @@
 [workspace]
 resolver = "2"
 members = [
-    "asap-common/sketch-core",
     "asap-common/dependencies/rs/promql_utilities",
     "asap-common/dependencies/rs/sql_utilities",
     "asap-common/dependencies/rs/elastic_dsl_utilities",
@@ -32,7 +31,6 @@ promql-parser = "0.5.0"
 tokio = { version = "1.0", features = ["full"] }
 
 # Internal crates
-sketch-core = { path = "asap-common/sketch-core" }
 promql_utilities = { path = "asap-common/dependencies/rs/promql_utilities" }
 sql_utilities = { path = "asap-common/dependencies/rs/sql_utilities" }
 asap_types = { path = "asap-common/dependencies/rs/asap_types" }