feat: node-scoped Networking operator page (#1603)

* feat: add node-scoped Networking operator page

Adds a Networking view with overview, topology, inventory, and findings.

Shared aggregate reads back the page; Resources keeps prune and redirects here.

Includes fail-closed network delete guards, operator docs, and /nodes/:slug/networking routing.

* fix: rename unused variable n to _n to satisfy no-unused-vars lint

* fix: keep top bar search clickable when nav grows

* feat: complete Compose-first Networking Phase 2 operator assistant

* fix: move networking action visibility helper out of component module

* feat(networking): complete Compose-first Networking operator page

Finish the node-scoped Networking page (Overview, Networks, Topology,
Findings) with design-system parity and correct finding semantics.

- Rebuild detail sheets on SystemSheet/SheetSection; align the tab band,
  masthead, and mobile tone with Fleet and Security.
- Encode the host-mode and exposure severity matrix; fix collision counts
  so intentional shared externals are not flagged; add one typed drift
  predicate shared by inventory, topology, badges, and overview counts.
- Preserve per-container attachments and IPs on topology node clicks;
  drawer-only click with an explicit logs action; ownership and boolean
  filters; bound large graphs before layout.
- Aggregate cached Compose Doctor findings into the Findings tab with
  honest source labels, structural merge and dedupe, staleness
  reconciliation, and a shared exposure-context helper both engines use.
- Networks tab: privacy-safe service search, precise ownership counts,
  schema v3 with version-2 adapters on every endpoint, pre-confirm delete
  reasons, and the shared sortable table with an internal scroll region.
- Interop: Fleet node-card networking signal with pending-intent
  navigation, stack-to-node backlink, and Dossier/Drift deep links.
- Enrich sanitized inspect with an allowlisted connected-container list;
  fetch topology once and filter client-side.
- Docs and tests across every new finding kind, adapter, and flow.

* fix(networking): correct drift count, exposure fail-soft, and inspect crash paths

Address code-review findings on the Networking page implementation:
- Fix the Overview drift count to use the shared drift-kind predicate instead
  of a hardcoded list that omitted external-network-missing.
- Gate Compose Doctor's unclassified-exposure and reverse-proxy-undocumented
  rules on exposure-context availability, so a DB read failure no longer
  fabricates findings (mirrors the live engine's existing fail-soft behavior).
- Guard the per-stack exposure-intent read in topology aggregation so a
  transient DB failure degrades to unknown intent instead of failing the
  whole response.
- Harden the network detail drawer against a partial inspect payload from an
  older remote node, and log the real error instead of a bare catch.
- Remove now-duplicated severity-rank and drift-kind helpers in favor of the
  shared modules; drop dead backend-only exports; widen the frontend schema
  version type to a plain number instead of casting past a literal type.
- Add coverage for the delete-guard precedence, the full host-mode severity
  matrix, the schema-2 compatibility adapter, and the sanitized connected-
  container allowlist; tighten two tests that were not exercising the
  behavior they claimed to.

* fix: add missing onOpenNodeNetworking prop to FleetView experimental test

The added required prop on FleetViewProps broke the merge-build when the
test file (on main but not on this branch) was compiled against the
updated FleetView interface.

backend/src/__tests__/preflight-rules.test.ts

@@ -32,6 +32,7 @@ function ctx(over: Partial<PreflightContext> = {}): PreflightContext {
     nodePorts: [], existingNetworkNames: new Set(), existingVolumeNames: new Set(),
     existingContainers: [], nodeStateAvailable: true, bindChecks: [],
     stackIntent: null, serviceIntents: {}, accessUrlPorts: new Set(), hasAccessUrls: false,
+    exposureAvailable: true,
     isSelfStack: false, ...over,
   };
 }
@@ -354,6 +355,15 @@ describe('exposure-intent rules', () => {
   it('does not warn unclassified when no port is published', () => {
     expect(ids(runRules(ctx({ model: model([svc()]), stackIntent: null })), 'exposure-unclassified')).toHaveLength(0);
   });
+  it('does not fabricate intent findings when the exposure context is unavailable', () => {
+    // A DB read failure leaves every intent null and no access URLs; the
+    // interpretation rules must stay silent rather than read that as unclassified
+    // or undocumented.
+    const rp = model([svc({ name: 'web', labelKeys: ['traefik.enable'], ports: [{ startPort: 8080, endPort: 8080, hostIp: '0.0.0.0', protocol: 'tcp' }] })]);
+    const f = runRules(ctx({ model: rp, exposureAvailable: false }));
+    expect(ids(f, 'exposure-unclassified')).toHaveLength(0);
+    expect(ids(f, 'reverse-proxy-undocumented')).toHaveLength(0);
+  });
   it('flags a published port absent from the documented access URLs', () => {
     const f = runRules(ctx({ model: withPort(), hasAccessUrls: true, accessUrlPorts: new Set([443]) }));
     expect(ids(f, 'exposure-port-vs-dossier')).toHaveLength(1);