refactor: rename Kopaya to Eryx

Rename the product, runtime surfaces, sidecar projects, docs, tests, and packaging outputs from Kopaya to Eryx across the repository.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/components/SettingsPanel.tsx

@@ -186,7 +186,7 @@ function ConnectionSection({
       <div className="mb-1">
         <h3 className="text-sm font-semibold text-zinc-200">GitHub Copilot</h3>
         <p className="mt-0.5 text-[12px] text-zinc-500">
-          Kopaya uses your installed GitHub Copilot CLI for AI capabilities
+          Eryx uses your installed GitHub Copilot CLI for AI capabilities
         </p>
       </div>
       <div className="mt-4 rounded-xl border border-[var(--color-border)] bg-zinc-900/30 p-4">

src/renderer/components/Sidebar.tsx

@@ -499,7 +499,7 @@ export function Sidebar({
             <Sparkles className="size-4" />
           </div>
           <div>
-            <span className="text-sm font-semibold text-zinc-100">kopaya</span>
+            <span className="text-sm font-semibold text-zinc-100">eryx</span>
             <span className="ml-1.5 rounded bg-zinc-800 px-1 py-0.5 text-[9px] font-medium text-zinc-500">
               BETA
             </span>

src/renderer/components/WelcomePane.tsx

@@ -21,7 +21,7 @@ export function WelcomePane({
         </div>
 
         <div>
-          <h1 className="text-xl font-semibold text-zinc-100">Welcome to kopaya</h1>
+          <h1 className="text-xl font-semibold text-zinc-100">Welcome to eryx</h1>
           <p className="mt-2 max-w-md text-sm leading-relaxed text-zinc-500">
             Start a scratchpad conversation for ad-hoc questions or connect a project to work with
             repo-aware Copilot agents.