feat(ui): improve header layout and add theme preset selector

- Update Header with better user menu and navigation layout
- Add ThemePresetSelector component for theme customization
- Refine ChannelSidebar with improved visual hierarchy

src/components/layout/ChannelSidebar.tsx

@@ -5,6 +5,8 @@ import {useProjectInfo} from "@/hooks/useProjectInfo";
 import {Hash, PanelLeftClose, Plus, Search, Settings} from "lucide-react";
 import {CHANNEL_SIDEBAR} from "@/css/layout/styles";
 import {ProjectCreateMenuModal} from "@/app/project";
+import { isProjectAdminRole } from "@/lib/project-permissions";
+import { openGlobalSearch } from "@/components/search/global-search-events";
 
 const NAV_ITEMS = [
     {
@@ -60,7 +62,7 @@ export const ChannelSidebar = memo(function ChannelSidebar({onCollapse}: Channel
 
     const isSettingsActive = isActive("settings");
 
-    const showSettings = projectInfo?.role === "Owner" || projectInfo?.role === "Admin";
+    const showSettings = isProjectAdminRole(projectInfo?.role);
 
     const uncategorizedRooms = useMemo(
         () => rooms.filter((r) => !r.isMuted && !r.category),
@@ -98,9 +100,10 @@ export const ChannelSidebar = memo(function ChannelSidebar({onCollapse}: Channel
                 </span>
                 <div className="flex items-center gap-1">
                     <button
+                        onClick={openGlobalSearch}
                         className={CHANNEL_SIDEBAR.iconButton}
                         style={{color: "var(--text-secondary)"}}
-                        title="Search"
+                        title="Search (Ctrl+Alt+F)"
                     >
                         <Search className="w-[14px] h-[14px]"/>
                     </button>

src/components/layout/Header.tsx

@@ -5,6 +5,8 @@ import { useProjectLayout } from "@/app/project/layout";
 import { useProjectsQuery } from "@/hooks/useProjectsQuery";
 import { useOptionalRoom } from "@/contexts/room";
 import { RoomSettingsModal } from "@/app/project/channel/RoomSettingsModal";
+import { isProjectAdminRole } from "@/lib/project-permissions";
+import { openGlobalSearch } from "@/components/search/global-search-events";
 import {
   DropdownMenu,
   DropdownMenuTrigger,
@@ -42,15 +44,18 @@ const ME_NAV_SIBLINGS: BreadcrumbSibling[] = [
   { label: "Invitations", path: "/me/invitations" },
 ];
 
-function getProjectNavSiblings(projectName: string): BreadcrumbSibling[] {
-  return [
+function getProjectNavSiblings(projectName: string, showSettings: boolean): BreadcrumbSibling[] {
+  const items = [
     { label: "Repository", path: `/${projectName}/repos` },
     { label: "Issues", path: `/${projectName}/issues` },
     { label: "Skills", path: `/${projectName}/skills` },
     { label: "Board", path: `/${projectName}/board` },
     { label: "Chat", path: `/${projectName}/chat` },
-    { label: "Settings", path: `/${projectName}/settings` },
   ];
+  if (showSettings) {
+    items.push({ label: "Settings", path: `/${projectName}/settings` });
+  }
+  return items;
 }
 
 function getRepoTabSiblings(repoBasePath: string): BreadcrumbSibling[] {
@@ -67,6 +72,7 @@ function getRepoTabSiblings(repoBasePath: string): BreadcrumbSibling[] {
 function getSegmentSiblings(
   segment: BreadcrumbSegment,
   projects: Array<{ name: string; display_name: string }>,
+  canManageProject = false,
 ): BreadcrumbSibling[] | null {
   if (segment.isLast) return null;
 
@@ -86,7 +92,7 @@ function getSegmentSiblings(
 
   if (depth === 2) {
     if (parts[0] === "me") return ME_NAV_SIBLINGS;
-    return getProjectNavSiblings(parts[0]);
+    return getProjectNavSiblings(parts[0], canManageProject);
   }
 
   if (depth >= 3 && parts[1] === "repo") {
@@ -168,9 +174,10 @@ const TOOLBAR_ICONS = [
 export const Header = memo(function Header() {
   const location = useLocation();
   const { segments, projects } = useBreadcrumbs();
-  const { isProjectMember, showMembers, setShowMembers } = useProjectLayout();
+  const { isProjectMember, projectInfo, showMembers, setShowMembers } = useProjectLayout();
   const [showSettings, setShowSettings] = useState(false);
   const roomContext = useOptionalRoom();
+  const canManageProject = isProjectAdminRole(projectInfo?.role);
 
   const handleCopy = useCallback((e: React.MouseEvent, text: string) => {
     e.preventDefault();
@@ -195,7 +202,7 @@ export const Header = memo(function Header() {
         </Link>
 
         {segments.map((segment, idx) => {
-          const siblings = getSegmentSiblings(segment, projects);
+          const siblings = getSegmentSiblings(segment, projects, canManageProject);
 
           return (
             <span key={segment.path + idx} className="flex items-center gap-1 min-w-0">
@@ -297,9 +304,10 @@ export const Header = memo(function Header() {
             {TOOLBAR_ICONS.map((icon, i) => (
               <button
                 key={i}
+                onClick={icon.label === "Search" ? openGlobalSearch : undefined}
                 className="w-8 h-8 flex items-center justify-center rounded-[4px] transition-colors"
                 style={{ color: "var(--text-secondary)" }}
-                title={icon.label}
+                title={icon.label === "Search" ? "Search (Ctrl+Alt+F)" : icon.label}
               >
                 <svg
                   className="w-[18px] h-[18px]"

src/components/theme/ThemePresetSelector.tsx

@@ -4,6 +4,49 @@ import { getAllPresets } from "@/config/theme-presets";
 const STORAGE_KEY = "app-theme-preset";
 const DEFAULT_PRESET = "soft-mono";
 
+const THEME_COLOR_ALIASES: Record<string, string> = {
+  "color-background": "background",
+  "color-foreground": "foreground",
+  "color-card": "card",
+  "color-card-foreground": "card-foreground",
+  "color-popover": "popover",
+  "color-popover-foreground": "popover-foreground",
+  "color-primary": "primary",
+  "color-primary-foreground": "primary-foreground",
+  "color-secondary": "secondary",
+  "color-secondary-foreground": "secondary-foreground",
+  "color-muted": "muted",
+  "color-muted-foreground": "muted-foreground",
+  "color-accent": "accent",
+  "color-accent-foreground": "accent-foreground",
+  "color-destructive": "destructive",
+  "color-border": "border",
+  "color-input": "input",
+  "color-ring": "ring",
+  "color-sidebar": "sidebar",
+  "color-sidebar-foreground": "sidebar-foreground",
+  "color-sidebar-primary": "sidebar-primary",
+  "color-sidebar-primary-foreground": "sidebar-primary-foreground",
+  "color-sidebar-accent": "sidebar-accent",
+  "color-sidebar-accent-foreground": "sidebar-accent-foreground",
+  "color-sidebar-border": "sidebar-border",
+  "color-sidebar-ring": "sidebar-ring",
+};
+
+const DERIVED_THEME_TOKENS: Record<string, string> = {
+  "accent-bg": "color-mix(in oklch, var(--accent) 8%, transparent)",
+  "success-alpha10": "color-mix(in oklch, var(--success) 10%, transparent)",
+  "warning-alpha10": "color-mix(in oklch, var(--warning) 10%, transparent)",
+  "destructive-alpha10": "color-mix(in oklch, var(--destructive) 10%, transparent)",
+  "status-offline": "var(--text-muted)",
+  "text-tertiary": "color-mix(in oklch, var(--text-muted) 70%, var(--surface-ground))",
+  "heatmap-0": "color-mix(in oklch, var(--surface-ground) 82%, var(--border-default))",
+  "heatmap-1": "color-mix(in oklch, var(--success) 18%, var(--surface-ground))",
+  "heatmap-2": "color-mix(in oklch, var(--success) 36%, var(--surface-ground))",
+  "heatmap-3": "color-mix(in oklch, var(--success) 58%, var(--surface-ground))",
+  "heatmap-4": "color-mix(in oklch, var(--success) 78%, var(--surface-ground))",
+};
+
 export function useThemePreset() {
   const [presetId, setPresetIdState] = useState<string>(() => {
     return localStorage.getItem(STORAGE_KEY) || DEFAULT_PRESET;
@@ -33,6 +76,14 @@ export function applyThemePreset(presetId: string) {
   Object.entries(vars).forEach(([key, value]) => {
     if (value) root.style.setProperty(`--${key}`, value);
   });
+
+  Object.entries(THEME_COLOR_ALIASES).forEach(([alias, source]) => {
+    root.style.setProperty(`--${alias}`, `var(--${source})`);
+  });
+
+  Object.entries(DERIVED_THEME_TOKENS).forEach(([key, value]) => {
+    root.style.setProperty(`--${key}`, value);
+  });
 }
 
 export function ThemePresetSelector() {