feat(ui): unify resource headings with responsive action menus

Add responsive overflow handling and dedicated action menus for application,
service, database, and server headings, while improving upgrade and email
settings flows and returning 404s for missing deployment environments.

DESIGN.md

@@ -154,6 +154,21 @@ topbar instead of repeating its name or status summary in layer 2. Mobile
 resource navigation may repeat this context because the desktop global topbar
 is hidden there.
 
+Desktop resource lifecycle actions dock in `#resource-action-hud-slot` and
+use `<x-resource-heading-overflow>`. Show primary actions (Deploy, Redeploy,
+Restart, Stop) as sibling header buttons. Collapse that group into an Actions
+dropdown only when the remaining top-bar width cannot fit them (breadcrumb
+keeps a 200px floor). Infrequent operations live in a separate Advanced
+dropdown with the grid icon: force restart / force deploy / force cleanup
+on services, and Traefik dashboard / refresh proxy status on servers. Place
+Advanced immediately after Links, or first in the action cluster when there
+is no Links control. Application Deploy is a dropdown with Deploy and
+Deploy (without cache). A running service Restart control is a dropdown with
+Restart current version and Pull latest and restart. Mobile
+headings keep a full-width Actions dropdown because the desktop HUD is hidden
+below `xl`. Do not hide primary actions behind a menu on a wide desktop. Links
+stay a separate dropdown because the URL list is unbounded.
+
 Only add layer-2 tabs when they represent real sibling routes inside one
 context. Never repeat main-sidebar destinations such as Dashboard, Projects,
 Terminal, Servers, Sources, Destinations, or Storage as a second tab row. A