query operator support in server filters

[ChuckHend]

To search such as query=iphones&product_category=eq.electronics&price=lte.1000 for iphones in electronics less than or equal to 1000 price.

[Copilot]

Pull Request Overview

This PR implements operators support in server filters, allowing search queries to use comparison operators like eq., gt., gte., lt., and lte. with filter values. The implementation includes comprehensive SQL injection protection, maintains backward compatibility with existing filters, and adds extensive test coverage.

• Complete redesign of the FilterValue type system to support operators with type-safe value parsing
• Implementation of SQL injection protection through pattern detection and input validation
• Addition of comprehensive test suite covering normal operations, edge cases, and security scenarios

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
server/tests/util.rs	Updated error handling to return Result types instead of panicking
server/tests/tests.rs	Added extensive test coverage for filter operators including backward compatibility and edge cases
server/src/routes/search.rs	Updated to use new FilterValue structure and handle different value types in query binding
core/src/query.rs	Major refactoring with new operator system, SQL injection protection, and comprehensive test suite

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