TypeScript 6.0 Enables --noImplicitOverride by Default

TypeScript 6.0 now enables --noImplicitOverride by default, requiring the override keyword on every method that overrides a parent implementation. The change catches inheritance bugs at compile time but forces teams to migrate existing class hierarchies.

• noImplicitOverride is on by default in TypeScript 6.0
• The override keyword is required on overriding methods
• Abstract and interface implementations do not need override
• Migration can be phased per-directory via tsconfig files