feat: add validator price consensus Venus example

[sanjeebdas1979]

Summary

Adds a new price-consensus Venus example that demonstrates how to aggregate multiple Rialo REX validator responses from a single HTTP price request and derive a deterministic median price.

What this example demonstrates

• Fetches live price data through Rialo REX validators
• Processes multiple validator responses from a RexReport
• Rejects failed, malformed, empty, or invalid responses
• Parses string-encoded prices into numeric values
• Normalizes prices into integer cents
• Computes min, max, and median consensus values
• Stores consensus statistics in persistent workflow state
• Includes a deployable PolkaVM artifact crate
• Includes generated WIT and Venus manifest files
• Adds the new example to the workspace

Workflow

1. initialize stores the price feed URL and symbol
2. check_price issues the asynchronous HTTP request
3. REX validators independently fetch the external endpoint
4. handle_price_report receives the aggregated validator report
5. Valid prices are collected and sorted
6. The median is stored as the consensus price

Validation

Tested end-to-end on Rialo Devnet using the Binance US BTC/USDT ticker endpoint.

Observed result:

• Validator responses: 4
• Valid responses: 4
• Rejected responses: 0
• Median consensus successfully calculated

Checks

• cargo check -p rialo-price-consensus
• cargo build --manifest-path venus/price-consensus/artifact/Cargo.toml
• git diff --cached --check

[vercel]

@sanjeebdas1979 is attempting to deploy a commit to the Subzero Labs Team on Vercel.

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