refactor(ui): full rewrite instance and code struct (#129)

## Summary by Sourcery

Refactor the UI to modernize effect handling, routing, and legacy APIs
while adding a reusable alert dialog component and cleaning up obsolete
stores.

New Features:
- Introduce a shared SaturnEffect context via ParticleBackground so
pages can access the effect without relying on global window APIs.
- Add a Base UI–powered alert dialog component for consistent
confirmation and warning flows across the app.
- Define a central router configuration module with instance routes to
standardize page wiring.

Bug Fixes:
- Ensure SaturnEffect nullish checks are handled safely when forwarding
pointer and touch events from the home view.

Enhancements:
- Rewrite ParticleBackground to manage its own SaturnEffect lifecycle
via React state and context instead of global accessors.
- Update the home view to use the SaturnEffect hook, simplify
pointer/touch handlers, and remove legacy game and release store usage.
- Refine layout and accessibility attributes for various form field and
label components, including field grouping and error rendering keys.
- Simplify sidebar navigation and adjust the user dropdown trigger to
work with the updated dropdown menu API.
- Wrap the root outlet for the home route with ParticleBackground only
on the index path to limit the effect to the intended view.
- Clean up imports and code style in radio group and other UI primitives
for consistency.

Chores:
- Remove deprecated UI stores and utility modules that are no longer
used with the new architecture.
- Add changeset entries documenting the Saturn effect refactor,
ParticleBackground rewrite, and removal of legacy store code.

1 files changed, 102 insertions, 0 deletions

diff --git a/packages/ui/src/pages/home.tsx b/packages/ui/src/pages/home.tsx
new file mode 100644
index 0000000..dc1413d
--- /dev/null
+++ b/packages/ui/src/pages/home.tsx
@@ -0,0 +1,102 @@
+import { useState } from "react";
+import { BottomBar } from "@/components/bottom-bar";
+import { useSaturnEffect } from "@/components/particle-background";
+
+export function HomePage() {
+  const [mouseX, setMouseX] = useState(0);
+  const [mouseY, setMouseY] = useState(0);
+  const saturn = useSaturnEffect();
+
+  const handleMouseMove = (e: React.MouseEvent) => {
+    const x = (e.clientX / window.innerWidth) * 2 - 1;
+    const y = (e.clientY / window.innerHeight) * 2 - 1;
+    setMouseX(x);
+    setMouseY(y);
+
+    // Forward mouse move to SaturnEffect (if available) for parallax/rotation interactions
+    saturn?.handleMouseMove(e.clientX);
+  };
+
+  const handleSaturnMouseDown = (e: React.MouseEvent) => {
+    saturn?.handleMouseDown(e.clientX);
+  };
+
+  const handleSaturnMouseUp = () => {
+    saturn?.handleMouseUp();
+  };
+
+  const handleSaturnMouseLeave = () => {
+    // Treat leaving the area as mouse-up for the effect
+    saturn?.handleMouseUp();
+  };
+
+  const handleSaturnTouchStart = (e: React.TouchEvent) => {
+    if (e.touches && e.touches.length === 1) {
+      const clientX = e.touches[0].clientX;
+      saturn?.handleTouchStart(clientX);
+    }
+  };
+
+  const handleSaturnTouchMove = (e: React.TouchEvent) => {
+    if (e.touches && e.touches.length === 1) {
+      const clientX = e.touches[0].clientX;
+      saturn?.handleTouchMove(clientX);
+    }
+  };
+
+  const handleSaturnTouchEnd = () => {
+    saturn?.handleTouchEnd();
+  };
+
+  return (
+    <div className="relative z-10 h-full overflow-y-auto custom-scrollbar scroll-smooth">
+      {/* Hero Section (Full Height) - Interactive area */}
+      <div
+        role="tab"
+        className="min-h-full flex flex-col justify-end p-12 pb-32 cursor-grab active:cursor-grabbing select-none"
+        onMouseDown={handleSaturnMouseDown}
+        onMouseMove={handleMouseMove}
+        onMouseUp={handleSaturnMouseUp}
+        onMouseLeave={handleSaturnMouseLeave}
+        onTouchStart={handleSaturnTouchStart}
+        onTouchMove={handleSaturnTouchMove}
+        onTouchEnd={handleSaturnTouchEnd}
+        tabIndex={0}
+      >
+        {/* 3D Floating Hero Text */}
+        <div
+          className="transition-transform duration-200 ease-out origin-bottom-left"
+          style={{
+            transform: `perspective(1000px) rotateX(${mouseY * -1}deg) rotateY(${mouseX * 1}deg)`,
+          }}
+        >
+          <div className="flex items-center gap-3 mb-6">
+            <div className="h-px w-12 bg-white/50"></div>
+            <span className="text-xs font-mono font-bold tracking-[0.2em] text-white/50 uppercase">
+              Launcher Active
+            </span>
+          </div>
+
+          <h1 className="text-8xl font-black tracking-tighter text-white mb-6 leading-none">
+            MINECRAFT
+          </h1>
+
+          <div className="flex items-center gap-4">
+            <div className="bg-white/10 backdrop-blur-md border border-white/10 px-3 py-1 rounded-sm text-xs font-bold uppercase tracking-widest text-white shadow-sm">
+              Java Edition
+            </div>
+          </div>
+        </div>
+
+        {/* Action Area */}
+        <div className="mt-8 flex gap-4">
+          <div className="text-zinc-500 text-sm font-mono">
+            &gt; Ready to launch session.
+          </div>
+        </div>
+
+        <BottomBar />
+      </div>
+    </div>
+  );
+}