refactor: rename Planarchy to CapaKraken (branding only)

User-facing rename across 20 files:
- Layout title/meta: "CapaKraken — Resource & Capacity Planning"
- Sidebar logo: "CapaKraken" with "RESOURCE & CAPACITY PLANNING"
- Sign-in page: "CapaKraken Control Center", "Sign in to CapaKraken"
- PWA manifest: name + short_name
- PDF reports: footer text
- Install prompt: "Install CapaKraken"
- AI assistant system prompt
- Webhooks test payload
- Email subject lines
- Tooltips, descriptions, empty states

NOT changed (technical identifiers):
- Package names (@planarchy/*)
- Import paths
- Database names
- Docker container names
- localStorage keys
- Domain URLs
- CLAUDE.md

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/app/auth/signin/page.tsx

@@ -37,7 +37,7 @@ export default function SignInPage() {
         <div className="hidden rounded-[2rem] border border-white/70 bg-white/75 p-10 shadow-2xl backdrop-blur lg:flex lg:flex-col lg:justify-between dark:border-slate-800 dark:bg-slate-950/60">
           <div>
             <span className="inline-flex rounded-full border border-brand-200 bg-brand-50 px-3 py-1 text-[11px] font-semibold uppercase tracking-[0.18em] text-brand-700 dark:border-brand-900/50 dark:bg-brand-900/20 dark:text-brand-300">
-              plANARCHY Control Center
+              CapaKraken Control Center
             </span>
             <h1 className="mt-6 font-display text-5xl font-semibold leading-tight text-gray-900 dark:text-gray-50">
               Resource planning that stays readable under pressure.
@@ -66,7 +66,7 @@ export default function SignInPage() {
           <div className="app-surface-strong p-8">
             <div className="mb-8">
               <p className="text-xs font-semibold uppercase tracking-[0.18em] text-brand-600">Welcome Back</p>
-              <h2 className="mt-3 font-display text-4xl font-semibold text-gray-900 dark:text-gray-50">Sign in to plANARCHY</h2>
+              <h2 className="mt-3 font-display text-4xl font-semibold text-gray-900 dark:text-gray-50">Sign in to CapaKraken</h2>
               <p className="mt-2 text-sm text-gray-500">Resource Planning, staffing, and forecasting.</p>
             </div>