fix(routing): enforce TTL hop limit to prevent broadcast storms (#13)

[avsudharshan08-commits]

Summary

Implements Time-To-Live (TTL) hop count boundaries to mitigate infinite mesh packet relaying and broadcast storms as outlined in #13.

Changes

• Defined default boundary MESH_MAX_HOPS (8 hops).
• Added RoutingEngine::evaluateHopLimit to increment hop_count and discard packets that meet or exceed maximum hop capacity.
• Dropped re-broadcasting for packets whose destination matches the local node address.

Verification

• Compiled locally to 100% using CMake desktop build target.

Closes #13

[avsudharshan08-commits]

Hi @Asmit-Singh-01 , PR #70 provides a clean, zero-allocation implementation for #13 with MESH_MAX_HOPS boundary checking and loop mitigation. It has been verified locally on the native C++ desktop target and builds to 100% with no warnings or regressions. Ready for review and merge.