Fix datetime input month formatting in Lit and Angular renderers

[RobinsonBeato]

Summary

Fixes an off-by-one error in datetime input renderers (Lit and Angular). In JavaScript, Date.getMonth() is zero-based (January = 0), which caused rendered month values to be incorrect.

Changes

• Normalize month formatting by using getMonth() + 1.
• Apply the fix consistently across Lit and Angular renderers.

Impact

Prevents incorrect month rendering in datetime inputs, avoiding user-facing data errors and improving UX consistency.