Add Web Push, guided start screen, SVG icons, chunked uploads, rename

- Web Push (VAPID + RFC 8291, pure Rust): permission/question/finished
  notifications while no app window is visible; settings with test button
- Guided new-session flow: task, craft target (website/app/game/old
  software/fresh), clean room or deep, description, model, folder
  (new, existing or cloned git repository); originals upload to original/
- Craft phase bar (craft_phase tool) for study/specify/build/check/ready
- Chunked uploads (8 MB) up to server.max_upload_mb (default 500 MB)
- All UI glyphs and emojis replaced by themeable SVG icons
- Rename dialog with manual name or model-generated suggestion

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/components/Budget.tsx

@@ -1,3 +1,4 @@
+import { Icon } from "./Icon";
 import { useFetch } from "../hooks";
 import { fmtCost, fmtPercent, useT } from "../i18n";
 
@@ -30,7 +31,7 @@ function Bar({ share, warning, exceeded }: { share: number; warning: boolean; ex
 
 function Remote({ r, t }: { r: BudgetRow["remote"]; t: ReturnType<typeof useT> }) {
   if (!r) return <span className="muted">–</span>;
-  if (r.error) return <span className="muted" title={r.error}>⚠ {t("budget.remoteError")}</span>;
+  if (r.error) return <span className="muted" title={r.error}><Icon name="warning" /> {t("budget.remoteError")}</span>;
   const cur = r.currency ?? "USD";
   if (r.spent_month !== undefined) return <span title={t("budget.orgWide")}>{t("budget.providerSpent", { v: fmtCost(r.spent_month, cur) })}</span>;
   if (r.remaining !== null && r.remaining !== undefined) return <span>{t("budget.balance", { v: fmtCost(r.remaining, cur) })}</span>;