Add Tests for Analytics Aggregator Contract Module

[Mosas2000]

Description

The analytics aggregator contract module has no tests. contracts/soroban/src/analytics_aggregator.rs is implemented but has no corresponding test file in contracts/soroban/tests/, so on-chain metric aggregation logic is untested.

Requirements and context

• Add an analytics_aggregator.test.rs covering aggregation flows
• Cover record, aggregate, and read paths
• Run under cargo test
• Follow the existing contract test conventions

Suggested execution

Fork the repo and create a branch

git checkout -b test/contract-analytics-aggregator

Implement changes

• Add the analytics aggregator test module
• Cover happy paths and edge cases
• Verify with cargo test

Example commit message

test: add tests for analytics aggregator contract module

Guidelines

• Assignment required before starting
• PR must include a closing reference to this issue
• Timeframe: 72 hours