Add biome no type assertion lint plugin and resolve violations in source code

[nnoce14]

Task: Integrate and enforce '@albertodeago/biome-plugin-no-type-assertion' across the repo

Background

CellixJS currently contains TypeScript code with type assertions that should be eliminated to improve type safety and maintainability. We want to enforce this via linting, using the 'no type assertion' rule from '@albertodeago/biome-plugin-no-type-assertion'.

Scope

• Install '@albertodeago/biome-plugin-no-type-assertion' and enable its lint rule in the monorepo biome configuration
• Run all lints on the repo and comprehensively address any reported violations in all source code files
  • Refactor all code to remove type assertions
  • For files ending in .test.ts, you may use the biome-ignore comment to exclude violations (if refactoring would require unreasonably large effort)
• Ensure all builds and tests pass following the refactoring

Acceptance Criteria

• '@albertodeago/biome-plugin-no-type-assertion' is listed in package.json and enabled in the biome config
• All source code files (excluding .test.ts test files) are free of type assertions and pass the lint rule
• .test.ts violations are only excluded using biome-ignore comments as necessary
• All builds (pnpm run build) and tests (pnpm run test and pnpm run verify) pass after code changes

Additional Notes

• No changes are required to address test file violations beyond the use of lint ignore comments
• This task is complete only when the lint rule is enforced repo-wide, and all code adheres to the updated linting requirements