v1.0.0 of otp_autofill_field

Self-contained Flutter OTP field: PIN UI with automatic Android SMS Retriever and iOS one-time-code keyboard autofill, plus a resend timer. No external OTP/PIN dependency. Changelog excerpt: Rebuilt as a self-contained plugin— no pin_code_fieldsor sms_autofilldependency. Both are reimplemented. - AutoOtpField— OTP field combining own PIN cells + own Android SMS Retriever bridge + iOS oneTimeCodekeyboard autofill. - OtpPinField— single-hidden-input PIN widget. Fixes the per-cell paste / soft-backspace / partial-autofill bugs of pin_code_fields. - OtpRetriever— own Android SMS Retriever bridge (native Kotlin plugin): leak-free, idempotent, timeout-aware. Fixes the `[...]