fix(ecstore): replace unbounded metadata cache with moka (#743) (#3970)

fix(ecstore): replace unbounded metadata cache with moka

Replace the manual Arc<RwLock<HashMap>> metadata cache with
moka::future::Cache, which provides:
- Built-in LRU eviction when max_capacity is reached
- Automatic TTL expiry via time_to_live (250ms)
- Lock-free concurrent reads
- Non-blocking invalidation

Fixes the memory leak risk from unbounded HashMap and the
all-or-nothing eviction logic that cleared all entries at once.

Closes #743

Co-authored-by: houseme <housemecn@gmail.com>

Cargo.lock

@@ -9287,6 +9287,7 @@ dependencies = [
  "md-5 0.11.0",
  "memmap2 0.9.11",
  "metrics",
+ "moka",
  "num_cpus",
  "opentelemetry",
  "opentelemetry_sdk",