Fix scan findings: price_aggregates table, env vars, zero-div checks

[buzzkillb]

Summary

• Add price_aggregates table to database.rs initialization
• Make shanghai_price_service.rs read UPDATE_INTERVAL_SECONDS from env var
• Add zero-check before division in bot.rs conversion calculations
• Remove duplicate comment in bot.rs

These fixes address the valid findings from the code scan.

Note

Low Risk

Overview
This pull request adds the missing price_aggregates table creation to the database initialization in src/database.rs. It updates src/shanghai_price_service.rs to read the UPDATE_INTERVAL_SECONDS value from an environment variable instead of a hard‑coded constant. In src/bot.rs, it inserts a zero‑check before division operations in conversion calculations and removes a duplicate comment. Additionally, it introduces a new GitHub Actions workflow file at .github/workflows/test.yml to configure testing.

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[gitzillabot]

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[gitzillabot]

Duplicate test function causes compilation failure

High Severity

The test_validate_price_invalid test function is duplicated and has an orphaned statement. Lines 144-149 now contain:

#[test]
fn test_validate_price_invalid() {
#[test]
fn test_validate_price_invalid() {
assert!(validate_price(-10.0).is_err());
assert!(validate_price(-10.0).is_err());

This causes a "function defined multiple times" error and the orphaned assert! outside any function body will fail to compile.

Suggested fix: Remove the duplicate lines. The test should have only one function declaration and one assertion for -10.0. Keep the existing assertions for f64::NAN and f64::INFINITY.