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>

AGENTS.md

@@ -140,6 +140,13 @@ conflict on, do an existence check instead.
 flag set to false was silently on. Use the `envBoolean` helper in
 `apps/api/src/lib/config.ts`.
 
+**Mutations must confirm themselves.** `<Toaster />` is mounted in `App.tsx`
+inside `ThemeProvider`; use `toast.success` / `toast.error` in every mutation's
+`onSuccess` / `onError`. The shadcn Toaster ships wired to `next-themes`, which
+PIG does not use — it was rewired to PIG's `useTheme`. Before that it was never
+mounted, so toasts already written in RecordSheets fired into nothing and every
+save completed in silence.
+
 **shadcn's `accent` is a SUBTLE surface, not the brand.** shadcn uses
 `bg-accent` for hover, focus and selected states — dropdown items, command
 rows, ghost buttons. The brand is `primary`. In `tailwind.config.js`, `accent`