SignalFlow Mini V1/RD3 — modern oval voice overlay

[docreo]

Creates the V1/RD3 public candidate without mutating the V1/RD2 rollback.

Changes:

• modern oval/pill listening and transcription overlay
• blue listening state and graphite/blue-grey transcription state
• rounded animated waveform bars
• preserves visible status words
• preserves F8, microphone capture, local whisper.cpp transcription, clipboard recovery, guarded paste, focus protection, and timing path
• extends public verifier for the RD3 overlay path

Rollback: rollback/signalflow-mini-v1-rd2-public-2026-09-10 at the exact pre-change main commit.

Acceptance state: source/candidate staged in Git; Windows PowerShell parser, compile, runtime, and human UI acceptance remain pending and should be completed before merge/release.