perf(runtime): add configurable Pedersen memoization

[heemankv]

Summary

• add opt-in memoization for Cairo Native runtime Pedersen hashing
• keep cache configuration, storage, counters, and focused tests isolated in src/pedersen_cache.rs; runtime.rs only performs cache lookup and insertion around the Pedersen call
• replace the hard-coded active capacity with startup configuration supplied by downstream Madara
• keep the default disabled and expose an 8,192-entry default capacity per native execution thread
• expose process-wide cumulative hit, miss, total-call, and capacity-clear snapshots using relaxed atomics
• retain set_pedersen_cache_enabled(bool) for compatibility while adding the complete configure_pedersen_cache(...) API

The cache remains thread-local for the native execution hot path. Its configured capacity therefore applies independently to each native worker thread, while the telemetry aggregates activity across the process.

Exact Madara dependency base

This PR is intentionally based on 7e263feb594cf95e0ec000a83520b9ed5c827855, the commit tagged v0.9.0-rc.6.

That is the exact source release resolved as cairo-native 0.9.0-rc.6 in madara-alliance/madara@daaacf0055fbea1dca67b49aab5a74426efbf49c. The PR base branch points directly to that tag commit, so the diff remains limited to the Pedersen-cache work needed by Madara.

Validation

• cargo test pedersen_cache: 2 passed
• cargo clippy --workspace --all-targets --all-features -- -D warnings: passed
• cargo fmt --all -- --check: passed
• git diff --check: passed
• downstream locked cargo check -p mc-exec: passed
• downstream locked cargo check -p madara: passed

Downstream integration: madara-alliance/madara#1250

[Mohiiit]

I didn't find a merge-blocking Rust correctness issue at this head. I left two non-blocking questions inline.

[Mohiiit]

The two review questions are addressed at this head, and I didn't find additional blocking issues.