feat: move projects to sidebar rail and speed up session switching (#506)

* feat: move projects from header tabs to left sidebar rail

* refactor: remove variant from git generation session context

* feat: implemented drandrop action for navrails

* refactor: improve sidebar drag-and-drop smoothness and remove floating overlay

* fix: prevent mobile nav rail touch from closing drawer and opening menu

* fix: hide header tabs on desktop

* fix: prevent session flicker when switching projects

* style: soften chat panel divider borders

* style: improve icon contrast across core navigation

* fix: stabilize session selection during project switching

* style: unify sidebar surfaces and transparent section layers

* style: remove UI shadows and keep only scroll shadow

* perf: speed up project switching with cached session loading

* perf: speed up Git changes view and background refresh

* perf: make session switching lighter and less aggressive

* perf: optimized sessions list loading while project switching

* perf: smooth chat rendering and reduce interaction spikes

* fix: restore reliable load older messages visibility

packages/ui/src/components/chat/SkillAutocomplete.tsx

@@ -148,7 +148,7 @@ export const SkillAutocomplete = React.forwardRef<SkillAutocompleteHandle, Skill
   return (
     <div
       ref={containerRef}
-      className="absolute z-[100] min-w-0 w-full max-w-[360px] max-h-60 bg-background border-2 border-border/60 rounded-xl shadow-md bottom-full mb-2 left-0 flex flex-col"
+      className="absolute z-[100] min-w-0 w-full max-w-[360px] max-h-60 bg-background border-2 border-border/60 rounded-xl shadow-none bottom-full mb-2 left-0 flex flex-col"
       style={style}
     >
       <ScrollableOverlay outerClassName="flex-1 min-h-0" className="px-0 pb-2" fillContainer={false}>