Add backups with S3, daily cost push, automation templates and a browser tool

- Daily backups (database + config) into <data_dir>/backups, keep N,
  optional upload to any S3-compatible bucket (SigV4, bucket pruning);
  settings panel with run-now, list and download
- Daily cost summary push at 20:00 (opt-in per user, preview button)
- Automations from templates (dependency check, security review, test
  health, daily summary, TODO report, docs freshness) via POST /jobs/create
- browser tool: headless Chromium over CDP – click, type, keys, waits,
  JavaScript, navigation, screenshots, console errors; requests to private
  network addresses are blocked (sub-resources and redirects included)
- Secrets masked in the config view: S3 secret key, metrics token
- Replace the remaining text arrows/refresh glyphs with SVG icons

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

server/src/app.rs

@@ -81,6 +81,8 @@ pub struct App {
     pub update: crate::update::UpdateState,
     /// Provider reachability (checked every 5 minutes).
     pub health: crate::health::Health,
+    /// Automatic backups (last result, run lock).
+    pub backup: crate::backup::BackupState,
 }
 
 /// What a user may do with a session.
@@ -121,6 +123,7 @@ impl App {
             push: crate::push::Push::new(&data),
             terminals: Default::default(),
             health: Default::default(),
+            backup: Default::default(),
             update: Default::default(),
         });
         crate::auth::bootstrap(&app)?;