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/Sidebar.tsx

@@ -1,3 +1,4 @@
+import { Icon } from "./Icon";
 import { cycleThemeMode, getThemeMode, onThemeChange } from "../theme";
 import { useEffect, useMemo, useState, useSyncExternalStore } from "react";
 import { get, post } from "../api";
@@ -123,7 +124,7 @@ export function Sidebar({ open, activeId, section }: { open: boolean; activeId?:
                   <span>{s.title || t("session.untitled")}</span>
                 </div>
                 <div className="sub">
-                  {s.shared && <span title={t("sidebar.shared")}>⇄ </span>}
+                  {s.shared && <span title={t("sidebar.shared")}><Icon name="share" className="tiny" /> </span>}
                   {basename(s.cwd)} · {s.agent} · {fmtRelative(s.updated_at)}
                 </div>
               </button>
@@ -138,25 +139,25 @@ export function Sidebar({ open, activeId, section }: { open: boolean; activeId?:
         </span>
         <ThemeModeButton />
         <button className="small ghost" onClick={() => post("/auth/logout").then(() => location.reload())}>
-          <span className="nav-icon" aria-hidden>🚪</span>
+          <Icon name="logout" className="nav-icon" />
           {t("nav.logout")}
         </button>
       </div>
       <div className="sidebar-foot">
         <button className={`ghost ${section === "files" ? "active" : ""}`} onClick={() => navigate("/files")}>
-          <span className="nav-icon" aria-hidden>📁</span>
+          <Icon name="folder" className="nav-icon" />
           {t("nav.files")}
         </button>
         <button className={`ghost ${section === "images" ? "active" : ""}`} onClick={() => navigate("/images")}>
-          <span className="nav-icon" aria-hidden>🖼️</span>
+          <Icon name="image" className="nav-icon" />
           {t("nav.images")}
         </button>
         <button className={`ghost ${section === "stats" ? "active" : ""}`} onClick={() => navigate("/stats")}>
-          <span className="nav-icon" aria-hidden>📊</span>
+          <Icon name="chart" className="nav-icon" />
           {t("nav.stats")}
         </button>
         <button className={`ghost ${section === "settings" ? "active" : ""}`} onClick={() => navigate("/settings")}>
-          <span className="nav-icon" aria-hidden>🔧</span>
+          <Icon name="wrench" className="nav-icon" />
           {t("nav.settings")}
         </button>
       </div>
@@ -168,7 +169,7 @@ export function Sidebar({ open, activeId, section }: { open: boolean; activeId?:
 function ThemeModeButton() {
   const t = useT();
   const mode = useSyncExternalStore(onThemeChange, getThemeMode);
-  const icon = mode === "auto" ? "◐" : mode === "light" ? "☀" : "☾";
+  const icon = <Icon name={mode === "auto" ? "theme-auto" : mode === "light" ? "sun" : "moon"} />;
   const label = t(mode === "auto" ? "settings.themeAuto" : mode === "light" ? "settings.themeLight" : "settings.themeDark");
   return (
     <button className="small ghost theme-toggle" onClick={cycleThemeMode} title={`${t("settings.themeToggle")} – ${label}`} aria-label={t("settings.themeToggle")}>