MnemosyneC v0.9.12

BP137 0.9.12 -- persistent browser authority + browser-as-primary routing: the plow queries the user own logged-in Google/Perplexity (always-on session; sign in via Settings -> Authorities) before the encyclopedia swarm, honest fallthrough when not signed in. Plus the HOT/COLD lift render crash fix. Behind one research_arm flag, default OFF. SHA-256 e06fe1578c5f98adce248d8e81a897bcc340d483adbf63c8237f3415242319a3. Unsigned build.