chore: consolidate all in-progress parallel-session WIP

Wholesale commit of every uncommitted change across the tree, at the user's
explicit request — host refactor-campaign W1 (native.rs facade + native/ dir,
library/ + mgmt/ splits), Android, core. These streams were mid-flight and not
individually built/tested together; this supersedes the per-session HOLD
markers. Consolidating so everything lands on main in one pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -3184,10 +3184,10 @@ dependencies = [
  "anyhow",
  "ksni",
  "libc",
+ "punktfunk-core",
  "rustls",
  "serde",
  "serde_json",
- "sha2",
  "ureq",
  "windows 0.62.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "windows-service",