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/components/AllocationSheet.tsx

@@ -37,6 +37,7 @@ import {
 } from '@/components/ui/sheet';
 import { Textarea } from '@/components/ui/textarea';
 import { ApiError, compactNumber, get, money, percent, post, shortDate } from '@/lib/api';
+import { toast } from 'sonner';
 
 export interface AvailabilityRow {
   commitmentId: string;
@@ -295,10 +296,24 @@ export function AllocationSheet({
           })
         : post<AllocationRecord>('/api/allocations', { ...body, status: values.status });
     },
-    onSuccess: async () => {
+    onSuccess: async (allocation, values) => {
       await refresh();
       onOpenChange(false);
+      // The sheet closes on success, so without this the only evidence the
+      // write landed is a number moving somewhere off-screen. Report what
+      // actually happened, in the units the seller was thinking in.
+      const hours = Number(allocation.gpuHours ?? values.gpuHours).toLocaleString();
+      toast.success(
+        values.kind === 'hold' ? 'Capacity held' : 'Capacity allocated',
+        {
+          description:
+            values.kind === 'hold'
+              ? `${hours} GPU-hours reserved. The hold releases automatically when it expires.`
+              : `${hours} GPU-hours committed. Margin and utilisation have been updated.`,
+        },
+      );
     },
+    onError: (error) => toast.error('Could not save', { description: errorMessage(error) }),
   });
   const release = useMutation({
     mutationFn: (id: string) =>
@@ -306,8 +321,16 @@ export function AllocationSheet({
         reason: releaseReason.trim() || undefined,
       }),
     onMutate: () => setReleaseError(null),
-    onSuccess: refresh,
-    onError: (error) => setReleaseError(errorMessage(error)),
+    onSuccess: async () => {
+      await refresh();
+      toast.success('Hold released', {
+        description: 'The capacity is available to sell again.',
+      });
+    },
+    onError: (error) => {
+      setReleaseError(errorMessage(error));
+      toast.error('Could not release the hold', { description: errorMessage(error) });
+    },
   });
 
   const chooseCommitment = (id: string) => {