P2R-02 slice 4: Repo tab — connection / bandwidth / maintenance

Three independent forms on /hosts/{id}/repo so saving one section
doesn't disturb the others:

* Connection: edits repo URL, username, password (pre-filled from
  the redacted GET /api/hosts/{id}/repo-credentials view; password
  field shows masked stored-creds placeholder; blank password = keep
  existing). On save, encrypts and pushes config.update to a
  connected agent.
* Bandwidth: host-wide upload/download caps (KB/s; blank = no cap)
  written via store.SetHostBandwidth. New REST endpoint
  PUT /api/hosts/{id}/bandwidth for JSON callers.
* Maintenance: forget/prune/check cadences + check subset %, with
  per-row enabled toggles. Reuses cronParser for validation;
  auto-seeds the row if a host pre-dates the migration.

Right-rail surfaces repo size, snapshot count, snapshots-by-tag
breakdown (counted from existing snapshot tag rows), and an
'untagged snapshots are left alone' note.

Danger-zone re-init button is rendered but disabled with a hint
pointing at P2R-09 (real implementation lands there).

Validation re-renders the page with the relevant form's banner and
all other section state intact. Successful saves redirect with a
?saved=<section> query param so the page surfaces a small ✓ saved
indicator on the relevant form.

ci.yml: bump golangci-lint-action v6→v7 (separate change picked up
in this commit).

internal/server/http/server.go

@@ -126,6 +126,10 @@ func (s *Server) routes(r chi.Router) {
 		r.Get("/hosts/{id}/repo-maintenance", s.handleGetRepoMaintenance)
 		r.Put("/hosts/{id}/repo-maintenance", s.handleUpdateRepoMaintenance)
 
+		// Host-wide bandwidth caps (host.bandwidth_up_kbps /
+		// bandwidth_down_kbps). Apply to every restic invocation.
+		r.Put("/hosts/{id}/bandwidth", s.handleUpdateHostBandwidth)
+
 		// Per-source-group Run-now (JSON variant). HTMX action is
 		// mounted at the equivalent path outside /api below — both
 		// resolve to the same handler, which sniffs HX-Request.
@@ -192,8 +196,12 @@ func (s *Server) routes(r chi.Router) {
 		r.Get("/hosts/{id}/sources/{gid}/edit", s.handleUISourceGroupEditGet)
 		r.Post("/hosts/{id}/sources/{gid}/edit", s.handleUISourceGroupSave)
 		r.Post("/hosts/{id}/sources/{gid}/delete", s.handleUISourceGroupDelete)
-		// Repo tab (slice 4 fills in body).
+		// Repo tab — connection / bandwidth / maintenance. Three
+		// independent forms so saving one doesn't touch the others.
 		r.Get("/hosts/{id}/repo", s.handleUIHostRepo)
+		r.Post("/hosts/{id}/repo/credentials", s.handleUIRepoCredentialsSave)
+		r.Post("/hosts/{id}/repo/bandwidth", s.handleUIRepoBandwidthSave)
+		r.Post("/hosts/{id}/repo/maintenance", s.handleUIRepoMaintenanceSave)
 		// Schedules tab + create/edit/delete forms.
 		r.Get("/hosts/{id}/schedules", s.handleUISchedulesList)
 		r.Get("/hosts/{id}/schedules/new", s.handleUIScheduleNewGet)