chore: bump eslint to 10.3.0 and migrate to flat config

[lahirumaramba]

ESLint v10 completely removes support for legacy .eslintrc files, this upgrade transitions the linter setup to modern Flat Config (eslint.config.mjs).

Key changes:

• Upgraded eslint from ^8.56.0 to 10.3.0.
• Added Flat Config dependencies: typescript-eslint, @eslint/js, and globals.
• Replaced legacy .eslintrc.js with eslint.config.mjs, maintaining rule parity, naming conventions, and ignore patterns.
• Streamlined "lint:src" and "lint:test" scripts to remove deprecated --ext .ts CLI flags.
• Resolved a new no-useless-assignment lint error caught by v10 in auth.spec.ts.
• Auto-fixed 27 redundant inline eslint-disable comments across the codebase.

Verification

• npm install completes successfully.
• npm run lint runs cleanly with 0 errors and 0 warnings across the repository.
• Unit tests (npm test) continue to pass successfully (6,238 tests passing cleanly).

[gemini-code-assist]

Code Review

This pull request migrates the project to ESLint 10 and the Flat Config system, updating devDependencies and removing obsolete inline lint-disable comments. Feedback identifies a discrepancy in Node.js engine requirements between the manifest and lockfile and suggests using a version range for the eslint dependency. Additionally, the reviewer points out potential regressions in linting coverage due to restricted file patterns and global ignores, recommends isolating test-specific globals, and notes leftover whitespace in the source files.

[lahirumaramba]

@gemini-code-assist review

[gemini-code-assist]

Code Review

This pull request migrates the project to ESLint's flat configuration format, updates ESLint to version 10, and removes numerous inline lint suppression comments across the codebase. The review feedback identifies a significant breaking change in the minimum Node.js requirement (bumped to version 22), inconsistent version pinning for the ESLint dependency, and the improper inclusion of Mocha globals in the base configuration for production source files.

[lahirumaramba]

@gemini-code-assist review

[gemini-code-assist]

Code Review

This pull request migrates the project to ESLint v10 and the Flat Config system, replacing the legacy configuration with eslint.config.mjs. The changes include upgrading ESLint dependencies, bumping the minimum Node.js engine requirement, and removing numerous legacy ESLint suppression comments across the codebase. Feedback suggests lowering the Node.js engine requirement to >=20.19.0 to maintain compatibility with the current LTS version and removing redundant file patterns in the ESLint configuration that conflict with global ignore rules.