Remove redundant standalone: true from all components

[bracyw]

Description

Angular 19+ defaults to standalone components, making standalone: true in the component decorator redundant. ~30+ components still explicitly set it.

Acceptance Criteria

• All standalone: true removed from component decorators in angular-client/
• Build and lint pass
• No behavioral change

Proposed Solution

Search for standalone: true across all component .ts files and remove. Mechanical change — no logic affected.