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/lib/theme/themes/flexoki-dark.json

@@ -12,12 +12,12 @@
       "base": "#DA702C",
       "hover": "#DA702C",
       "active": "#F9AE77",
-      "foreground": "#111010",
+      "foreground": "#151313",
       "muted": "#DA702C80",
       "emphasis": "#F9AE77"
     },
     "surface": {
-      "background": "#111010",
+      "background": "#151313",
       "foreground": "#CECDC3",
       "muted": "#1C1B1A",
       "mutedForeground": "#878580",
@@ -40,19 +40,19 @@
     },
     "status": {
       "error": "#D14D41",
-      "errorForeground": "#111010",
+      "errorForeground": "#151313",
       "errorBackground": "#AF302920",
       "errorBorder": "#AF302950",
       "warning": "#DA702C",
-      "warningForeground": "#111010",
+      "warningForeground": "#151313",
       "warningBackground": "#BC521520",
       "warningBorder": "#BC521550",
       "success": "#A0AF54",
-      "successForeground": "#111010",
+      "successForeground": "#151313",
       "successBackground": "#66800B20",
       "successBorder": "#66800B50",
       "info": "#4385BE",
-      "infoForeground": "#111010",
+      "infoForeground": "#151313",
       "infoBackground": "#205EA620",
       "infoBorder": "#205EA650"
     },
@@ -138,9 +138,9 @@
     },
     "chat": {
       "userMessage": "#CECDC3",
-      "userMessageBackground": "#2E1B10",
+      "userMessageBackground": "#27180E",
       "assistantMessage": "#CECDC3",
-      "assistantMessageBackground": "#111010",
+      "assistantMessageBackground": "#151313",
       "timestamp": "#878580",
       "divider": "#343331"
     },