feat: Phase 4-5 — demo mode, polish, deploy, and bug fixes

Add demo mode with mock data provider, Docker deployment, Playwright
tests, PostHog analytics, error boundaries, and SEO metadata. Fix
residences API response unwrapping, kanban drag-and-drop with optimistic
updates, trailing slash proxy redirects, and column name mismatches with
Go API.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/residences/residence-card.tsx

@@ -1,8 +1,11 @@
+"use client";
+
 import Link from "next/link";
 import { MapPin } from "lucide-react";
 
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { Badge } from "@/components/ui/badge";
+import { useDataProvider } from "@/lib/demo/data-provider-context";
 import type { MyResidenceResponse } from "@/lib/api/residences";
 
 interface ResidenceCardProps {
@@ -11,19 +14,21 @@ interface ResidenceCardProps {
 
 export function ResidenceCard({ data }: ResidenceCardProps) {
   const { residence, task_summary } = data;
+  const { basePath } = useDataProvider();
 
   const address = [residence.street_address, residence.city, residence.state_province]
     .filter(Boolean)
     .join(", ");
 
   return (
-    <Link href={`/app/residences/${residence.id}`} className="block">
+    <Link href={`${basePath}/residences/${residence.id}`} className="block">
       <Card className="transition-colors hover:border-primary/40">
         <CardHeader>
           <CardTitle className="text-base">{residence.name}</CardTitle>
           {address && (
             <div className="flex items-center gap-1.5 text-sm text-muted-foreground">
-              <MapPin className="size-3.5 shrink-0" />
+              <MapPin className="size-3.5 shrink-0" aria-hidden="true" />
+              <span className="sr-only">Address:</span>
               <span className="truncate">{address}</span>
             </div>
           )}