Make mutations confirm themselves, and seed the evidence trail

Two demo gaps, both of which made working features look like they were not
there.

**Toasts fired into nothing.** RecordSheets already called toast.success on
every save, but <Toaster /> was never mounted, so nothing appeared. It could
not be mounted, either: the shadcn original imports next-themes, which PIG does
not use — it has its own provider so a chosen theme is persisted server-side
and follows a user between devices. Rewired to PIG's useTheme, mounted inside
ThemeProvider, and offset clear of the phone tab bar and the home indicator.

Feedback added where the interface otherwise gives none: allocation and hold
report the GPU-hours actually written, because the sheet closes on success and
the only other evidence is a number moving off-screen; releasing a hold says
the capacity is sellable again; fact decisions say what the decision meant, and
that approving evidence is not the same as writing it to a record; the profile
form confirms rather than just clearing itself, which otherwise reads as the
input being discarded.

**The fact table was empty**, so the review queue and every provenance tooltip
had nothing to show — the mechanism that makes an agent-written CRM
trustworthy, invisible. Six agent-derived facts seeded with a deliberate mix:
two applied, showing what a confident agent writes unprompted, and four
proposed, including one weak claim that a reviewer should reject, so the queue
is not a row of obvious approvals. Each carries a score, a band, evidence and
where available a source. Idempotent on subject+field+value; verified over two
runs.

Verified: toast confirmed firing in a real browser on a 393px viewport, 135
unit tests and e2e green, typecheck clean, CSP hash unchanged, 0px horizontal
overflow across 12 routes at both breakpoints.

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

apps/web/src/pages/Settings.tsx

@@ -14,6 +14,7 @@ import { Badge, Button, Card, CardContent, CardHeader, CardTitle, Input } from '
 import { useState } from 'react';
 import { usePageTitle } from '@/lib/title';
 import { AdminSettings } from '@/components/AdminSettings';
+import { toast } from 'sonner';
 
 interface Me {
   id: string;
@@ -144,7 +145,11 @@ function Profile({ me }: { me: Me | undefined }) {
       void queryClient.invalidateQueries({ queryKey: ['me'] });
       setName('');
       setTitle('');
+      // The form clears itself on success, which without confirmation reads as
+      // though the input was discarded rather than saved.
+      toast.success('Profile saved');
     },
+    onError: () => toast.error('Could not save your profile'),
   });
 
   if (!me) return null;