Feature/global search

[Timmoth]

Adds a search palette in the header (right of the rackpeek logo) for
jumping
straight to a resource by name, IP, tag, or label — addressing the user
request for "intent-based navigation" as the inventory grows.

• New <GlobalSearch> component in Shared.Rcl/Components/ wired into
  MainLayout — visible on every page.
• GlobalSearchService ranks resources against the query with weighted
  field priorities (name 100 > ip 50 > tag 25 > label 10) and match-shape
  modifiers (equality > prefix > substring > subsequence). No external
  dependencies; ~20 lines of scoring logic.
• Top 8 results render in a dropdown showing {name} · {kind} · via {matched-field}: {value}, so the user sees why each result appeared.
• Click navigates to the resource detail page via NavigationManager
  (resolves the URL via the existing Resource.GetResourceUrl).
• Keyboard: ↑/↓ to highlight, Enter to navigate, Esc to clear.
• Clicking outside the input closes the dropdown (@onfocusout with a
  150ms delay so result clicks still register).
• Inventory is re-queried on each keystroke so new/edited/deleted
  resources show up without a page refresh. The repo's already in-memory,
  so the cost is negligible.

Searchable kinds: every hardware sub-kind (server, switch, firewall,
router, accesspoint, ups, desktop, laptop), system, service.