feat: add SidecarManager actor pattern, SPKI pinning, btmsg seen_messages, Aider autonomous mode

Tribunal priorities 1-4: SidecarManager refactored to mpsc actor thread
(eliminates TOCTOU race), SPKI TOFU certificate pinning for relay TLS,
per-message btmsg acknowledgment via seen_messages table, Aider
autonomous mode toggle gating shell execution.

v2/Cargo.lock

@@ -15,8 +15,10 @@ dependencies = [
  "bterminal-core",
  "dirs 5.0.1",
  "futures-util",
+ "hex",
  "keyring",
  "log",
+ "native-tls",
  "notify",
  "notify-rust",
  "opentelemetry",
@@ -26,12 +28,14 @@ dependencies = [
  "rusqlite",
  "serde",
  "serde_json",
+ "sha2",
  "tauri",
  "tauri-build",
  "tauri-plugin-dialog",
  "tauri-plugin-updater",
  "tempfile",
  "tokio",
+ "tokio-native-tls",
  "tokio-tungstenite",
  "tracing",
  "tracing-opentelemetry",