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/Activity.tsx

@@ -1,3 +1,4 @@
+import { Icon } from "./Icon";
 import { useEffect, useState } from "react";
 import { fmtCompact, useT } from "../i18n";
 import { useStore, type Draft } from "../store";
@@ -143,8 +144,8 @@ export function ActivityLine({
       <span className="activity-text">{label}</span>
       {step && (
         <span className="activity-meta">
-          ({fmtElapsed(elapsed)} · ↑ {step.estimated ? "~" : ""}
-          {fmtCompact(step.promptTokens)} {t("activity.prefill")} · ↓ {prefill ? t("activity.prefilling") : `${fmtCompact(generated)} ${t("activity.generated")}`})
+          ({fmtElapsed(elapsed)} · <Icon name="arrow-up" className="tiny" /> {step.estimated ? "~" : ""}
+          {fmtCompact(step.promptTokens)} {t("activity.prefill")} · <Icon name="arrow-down" className="tiny" /> {prefill ? t("activity.prefilling") : `${fmtCompact(generated)} ${t("activity.generated")}`})
         </span>
       )}
     </div>
@@ -163,8 +164,8 @@ export function useTitleActivity() {
   const waiting = useStore((s) => s.permissions.length + s.questions.length);
   useEffect(() => {
     const base = "CodeCraft";
-    if (waiting > 0) document.title = `● ${t("activity.titleInput")} – ${base}`;
-    else if (busyCount > 0) document.title = `⏳ ${t("activity.titleBusy", { n: busyCount })} – ${base}`;
+    if (waiting > 0) document.title = `(!) ${t("activity.titleInput")} – ${base}`;
+    else if (busyCount > 0) document.title = `(${busyCount}) ${t("activity.titleBusy", { n: busyCount })} – ${base}`;
     else document.title = base;
   }, [busyCount, waiting, t]);
 }