feature: Add shadcn Tooltips to AppHeader for better UX

- Migrated serial number tooltip from native title to shadcn Tooltip
  - Shows formatted machine details (serial, MAC, total stitches, service count)
  - Better multi-line formatting with proper spacing

- Added tooltip to machine status badge
  - Shows state description explaining current status

- Added tooltip to auto-refresh spinner
  - Shows "Auto-refreshing machine status"

- Removed redundant title attributes
  - Disconnect button already has clear label
  - Error button has Popover for details

Benefits:
- Consistent tooltip styling across the app
- Better accessibility with ARIA attributes
- Improved readability with proper formatting
- Better positioning and animations

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/components/AppHeader.tsx

@@ -15,6 +15,12 @@ import {
 import { Button } from "@/components/ui/button";
 import { Badge } from "@/components/ui/badge";
 import { Popover, PopoverTrigger } from "@/components/ui/popover";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipProvider,
+  TooltipTrigger,
+} from "@/components/ui/tooltip";
 import { cn } from "@/lib/utils";
 
 export function AppHeader() {
@@ -61,6 +67,7 @@ export function AppHeader() {
   const StatusIcon = stateIcons[stateVisual.iconName];
 
   return (
+    <TooltipProvider>
       <header className="bg-gradient-to-r from-primary-600 via-primary-700 to-primary-800 dark:from-primary-700 dark:via-primary-800 dark:to-primary-900 px-4 sm:px-6 lg:px-8 py-3 shadow-lg border-b-2 border-primary-900/20 dark:border-primary-800/30 flex-shrink-0">
         <div className="grid grid-cols-1 lg:grid-cols-[280px_1fr] gap-4 lg:gap-8 items-center">
           {/* Machine Connection Status - Responsive width column */}
@@ -79,30 +86,49 @@ export function AppHeader() {
                   Respira
                 </h1>
                 {isConnected && machineInfo?.serialNumber && (
-                <span
+                  <Tooltip>
-                  className="text-xs text-primary-200 cursor-help"
+                    <TooltipTrigger asChild>
-                  title={`Serial: ${machineInfo.serialNumber}${
+                      <span className="text-xs text-primary-200 cursor-help">
-                    machineInfo.macAddress
-                      ? `\nMAC: ${machineInfo.macAddress}`
-                      : ""
-                  }${
-                    machineInfo.totalCount !== undefined
-                      ? `\nTotal stitches: ${machineInfo.totalCount.toLocaleString()}`
-                      : ""
-                  }${
-                    machineInfo.serviceCount !== undefined
-                      ? `\nStitches since service: ${machineInfo.serviceCount.toLocaleString()}`
-                      : ""
-                  }`}
-                >
                         • {machineInfo.serialNumber}
                       </span>
+                    </TooltipTrigger>
+                    <TooltipContent className="max-w-xs">
+                      <div className="text-sm space-y-1">
+                        <p className="font-semibold">
+                          Serial: {machineInfo.serialNumber}
+                        </p>
+                        {machineInfo.macAddress && (
+                          <p className="text-xs">
+                            MAC: {machineInfo.macAddress}
+                          </p>
+                        )}
+                        {machineInfo.totalCount !== undefined && (
+                          <p className="text-xs">
+                            Total stitches:{" "}
+                            {machineInfo.totalCount.toLocaleString()}
+                          </p>
+                        )}
+                        {machineInfo.serviceCount !== undefined && (
+                          <p className="text-xs">
+                            Stitches since service:{" "}
+                            {machineInfo.serviceCount.toLocaleString()}
+                          </p>
+                        )}
+                      </div>
+                    </TooltipContent>
+                  </Tooltip>
                 )}
                 {isPolling && (
-                <ArrowPathIcon
+                  <Tooltip>
-                  className="w-3.5 h-3.5 text-primary-200 animate-spin"
+                    <TooltipTrigger asChild>
-                  title="Auto-refreshing status"
+                      <div>
-                />
+                        <ArrowPathIcon className="w-3.5 h-3.5 text-primary-200 animate-spin" />
+                      </div>
+                    </TooltipTrigger>
+                    <TooltipContent>
+                      <p className="text-xs">Auto-refreshing machine status</p>
+                    </TooltipContent>
+                  </Tooltip>
                 )}
               </div>
               <div className="flex items-center gap-2 mt-1 min-h-[32px]">
@@ -113,19 +139,25 @@ export function AppHeader() {
                       size="sm"
                       variant="outline"
                       className="gap-1.5 bg-white/10 hover:bg-danger-600 text-primary-100 hover:text-white border-white/20 hover:border-danger-600 flex-shrink-0"
-                    title="Disconnect from machine"
                       aria-label="Disconnect from machine"
                     >
                       <XMarkIcon className="w-3 h-3" />
                       Disconnect
                     </Button>
+                    <Tooltip>
+                      <TooltipTrigger asChild>
                         <Badge
                           variant="outline"
-                    className="gap-1.5 px-2.5 py-1.5 sm:py-1 text-sm font-semibold bg-white/20 text-white border-white/30 flex-shrink-0"
+                          className="gap-1.5 px-2.5 py-1.5 sm:py-1 text-sm font-semibold bg-white/20 text-white border-white/30 flex-shrink-0 cursor-help"
                         >
                           <StatusIcon className="w-3 h-3" />
                           {machineStatusName}
                         </Badge>
+                      </TooltipTrigger>
+                      <TooltipContent>
+                        <p className="text-xs">{stateVisual.description}</p>
+                      </TooltipContent>
+                    </Tooltip>
                   </>
                 ) : (
                   <p className="text-xs text-primary-200">Not Connected</p>
@@ -143,7 +175,6 @@ export function AppHeader() {
                           ? "animate-pulse hover:animate-none"
                           : "invisible pointer-events-none",
                       )}
-                    title="Click to view error details"
                       aria-label="View error details"
                       disabled={!(machineErrorMessage || pyodideError)}
                     >
@@ -201,5 +232,6 @@ export function AppHeader() {
           </div>
         </div>
       </header>
+    </TooltipProvider>
   );
 }