Polish: per-route titles and a way to sign out

There was no sign-out control anywhere. Easy to miss when you develop
permanently signed in, and a stranded feeling for anyone on a shared machine.
Clearing the identity provider's session is sufficient — PIG holds no session
of its own — and the auth listener returns to sign-in without a reload. A hard
redirect follows regardless, so a failed provider call cannot leave a
half-signed-out interface.

Every route now sets its own document title. A single static title makes
browser history and a wall of tabs useless: every entry reads "pig" and nobody
can tell the margin view from the pipeline.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/web/src/pages/Capacity.tsx

@@ -9,6 +9,7 @@ import { useState } from 'react';
 import { useMutation, useQuery } from '@tanstack/react-query';
 import { Search, Server, Zap } from 'lucide-react';
 import { compactNumber, get, money, percent, post, shortDate } from '@/lib/api';
+import { usePageTitle } from '@/lib/title';
 import {
   Badge,
   Button,
@@ -42,6 +43,7 @@ interface AvailabilityRow {
 type MatchRow = AvailabilityRow & { score: number; rationale: string[] };
 
 export function Capacity() {
+  usePageTitle('Capacity');
   const [tab, setTab] = useState<'available' | 'match'>('available');
 
   return (