feat: onboarding polish, splash screen, controller nav, dev script

Onboarding flow:
- Intro: improved layout and transitions
- DID: better card styling and responsiveness
- Path: added visual enhancements
- Backup/Identity/Verify: streamlined markup
- SplashScreen component added

UI:
- Controller navigation improvements (useControllerNav)
- Style.css refinements

Backend:
- Runtime package fix

Dev:
- dev-start.sh improvements

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

core/archipelago/src/api/rpc/package/runtime.rs

@@ -7,7 +7,7 @@ use anyhow::{Context, Result};
 /// Per-container graceful shutdown timeout in seconds.
 /// Bitcoin Core needs 600s to flush UTXO set, LND 330s for channel state,
 /// indexers 300s for index flush, databases 120s for WAL/transaction commit.
-fn stop_timeout_secs(container_name: &str) -> &'static str {
+pub fn stop_timeout_secs(container_name: &str) -> &'static str {
     let id = container_name.strip_prefix("archy-").unwrap_or(container_name);
     match id {
         "bitcoin-knots" | "bitcoin-core" | "bitcoin" => "600",