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>

server/src/tools/mod.rs

@@ -159,6 +159,7 @@ pub fn builtin_tools() -> Vec<Arc<dyn Tool>> {
         Arc::new(crate::shells::KillShell),
         Arc::new(web::WebFetch),
         Arc::new(web::WebSearch),
+        Arc::new(agent::CraftPhase),
         Arc::new(crate::lsp::Diagnostics),
         Arc::new(agent::TodoWrite),
         Arc::new(agent::AskUser),