chore: land tree view-state, vault, Pi module split, and repo hygiene

Persist PageTree expand state via control-plane view-state and align
chevron/DOM with restored expansion; keep Sidex-style shallow page-tree
scan and drop the unused recursive scanner that only added cargo noise.

Add password vault workbench routes/runtime/skill/CLI, split page_ai_pi
into a module package, and retire Hermes/ACP/OpenHub recycle + root
harness evidence from the index while gitignoring recycle and local
diag dumps.

Archive superseded design/bugs docs under old/, point architecture at
ARCHITECTURE.md, and refresh smokes for Pi S1–S7, vault, and editor
regressions so the working tree can stay clean.

rust/crates/mnote-web/src/app.rs

@@ -18,6 +18,7 @@ use std::fs;
 use std::sync::Arc;
 #[cfg(not(test))]
 use std::time::Duration;
+use tower_http::compression::CompressionLayer;
 use tower_http::trace::TraceLayer;
 use tracing::{error, warn};
 
@@ -332,6 +333,9 @@ fn open_turso_synced_control_plane_store() -> Arc<dyn ControlPlaneStore> {
 
 pub fn build_app(state: AppState) -> Router {
     build_router(state)
+        // Outer layers run first on request / last on response. Compress HTML/JSON
+        // for large local-folder SSR shells (PageTree/FileTree).
+        .layer(CompressionLayer::new())
         .layer(TraceLayer::new_for_http().on_failure(()))
         .layer(axum::middleware::from_fn(log_failed_response))
         .layer(axum::middleware::from_fn(inject_request_context))