[FSSDK-12880] Refactor project config creation

[raju-opti]

Summary

• Simplify createProjectConfig to accept a datafile string directly instead of string | object, inlining datafile validation
• Remove the separate config_validator module and its tests
• Break monolithic config builder into focused parse functions: parseAudienceConfig, parseAttributeConfig, parseGroupConfig, parseRolloutConfig, parseIntegrationConfig, parseExperimentConfig, parseFeatureFlagConfig
• Eliminate mutation-safe datafile copy in favor of direct construction
• Refactor redundant iterations over experiments and feature flags
• Remove lodash dev dependency

Benchmarks show ~10% faster config parsing for 3-4 MB datafiles. Removing createMutationSafeDatafileCopy also fixes a memory issue where it allocated ~4x the datafile size in shallow copies per call, causing OOM under repeated parsing of large datafiles.

Test plan

• all existing tests pass after the modification to accommodate the API change

Issues

• FSSDK-12880

[coveralls]

coverage: 77.724% (+0.02%) from 77.701% — raju/config-refactor into master

[Copilot]

Pull request overview

This PR refactors project config creation to parse directly from a datafile JSON string, removes the standalone config_validator module (and its tests), and drops lodash as a dev dependency. The refactor also splits config parsing into more focused parse functions and streamlines iteration over experiments/feature flags for better performance and memory usage.

Changes:

• Change createProjectConfig to accept a datafile JSON string, inline basic parsing/version validation, and remove tryCreatingProjectConfig.
• Refactor config parsing into focused parse* helpers and reduce redundant iteration over rules/variations.
• Remove config_validator and lodash usage across tests; update call sites and mocks to pass JSON strings.

Reviewed changes

Copilot reviewed 25 out of 26 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
package.json	Removes lodash dev dependency.
package-lock.json	Updates lockfile due to dependency changes (includes several transitive bumps).
lib/utils/config_validator/index.ts	Removes datafile validation module (superseded by inline validation).
lib/utils/config_validator/index.tests.js	Removes mocha tests for config_validator.
lib/utils/config_validator/index.spec.ts	Removes vitest tests for config_validator.
lib/tests/mock/mock_datafile_manager.ts	Updates mock DatafileManager to operate on string datafiles only.
lib/project_config/project_config.ts	Refactors config parsing, inlines JSON parsing/version validation, removes tryCreatingProjectConfig.
lib/project_config/project_config.tests.js	Updates tests to pass stringified datafiles; adjusts expectations for ordering.
lib/project_config/project_config.spec.ts	Updates TS tests to pass stringified datafiles; updates option-based validation tests.
lib/project_config/project_config_manager.ts	Switches to createProjectConfig(datafileStr, options) and updates types to string-only datafile.
lib/project_config/project_config_manager.spec.ts	Updates config manager specs to use stringified datafiles and updated validation behavior.
lib/project_config/optimizely_config.tests.js	Removes lodash cloneDeep usage; updates to stringified createProjectConfig calls.
lib/project_config/optimizely_config.spec.ts	Removes local cloneDeep helper; updates to stringified createProjectConfig calls.
lib/optimizely/index.tests.js	Updates mock configs to use stringified createProjectConfig calls.
lib/optimizely/index.spec.ts	Updates TS tests to use stringified createProjectConfig calls.
lib/optimizely_user_context/index.tests.js	Updates tests to use stringified createProjectConfig calls.
lib/optimizely_user_context/index.spec.ts	Updates TS tests to use stringified createProjectConfig calls.
lib/index.react_native.spec.ts	Removes config_validator import; updates commented examples to stringified createProjectConfig.
lib/index.node.tests.js	Removes config_validator import; updates commented examples to stringified createProjectConfig.
lib/index.browser.umdtests.js	Removes config_validator usage in UMD tests.
lib/index.browser.tests.js	Removes config_validator import; updates to stringified createProjectConfig in mocks.
lib/event_processor/event_builder/user_event.spec.ts	Updates tests to pass stringified datafiles to createProjectConfig.
lib/core/decision_service/index.tests.js	Updates tests to use stringified createProjectConfig calls.
lib/core/decision_service/index.spec.ts	Updates TS tests to use stringified createProjectConfig calls.
lib/core/bucketer/index.tests.js	Updates tests to use stringified createProjectConfig calls.
lib/core/bucketer/index.spec.ts	Updates TS tests to use stringified createProjectConfig calls.

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[junaed-optimizely]

Good improvement! LGTM! I have just added one non-blocking comment