feat(apt): analyse des dépôts APT (lecture seule) (tâche 4)

- template repositories (deb lines + deb822), non destructif
- analyzeRepositories (TDD) : composants, repos, détection Proxmox
  enterprise/no-subscription, warnings (pve_enterprise_without_subscription,
  pve_repo_missing) + notes Debian/Ubuntu composants manquants
- route POST /machines/:id/apt-repositories ; api analyzeRepositories
- popup config : bloc « Dépôts APT » (composants + warnings + notes)

Analyse uniquement (modification = action validée séparée, future). tsc 0 · 113 tests · build OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

shared/types.ts

@@ -208,6 +208,15 @@ export interface RebootResult {
   errors?: SnapshotError[];
 }
 
+export interface AptRepositoriesAnalysis {
+  osFamily: OsFamily;
+  components: string[];
+  repos: { uri: string; suite: string; components: string[] }[];
+  proxmox?: { enterprise: boolean; noSubscription: boolean };
+  warnings: { kind: string; message: string }[];
+  notes: string[];
+}
+
 export interface MachineMetricsSimple {
   collectedAt: string;
   cpu: { load1: number | null; load5: number | null; cores: number | null };