merge: reconcile perf/wave1-perf with main (Wave 0 features)

Resolve conflicts from main's Wave 0 (PR #1) landing after this branch was cut:

- useViewResource.ts: main's e352aae already fixes the render loop the same way
  (load in a ref, dropped from deps) — took main's canonical version. My
  independent fix is superseded (my branch predated e352aae, which is why the
  loop reproduced live).
- JobApplicationsController.cs: keep BOTH main's IJobCvMatchService and my
  AnalyticsService (ctor gets both optional params). GetAnalyticsOverview stays
  delegated to AnalyticsService.
- Fold main's H3 additions into the extracted AnalyticsService: pipeline-driven
  funnel (JobPipeline.Normalize/Stages) + time-in-stage (StageAnalytics) and add
  StageDurationDto + TimeInStage to Models/AnalyticsDtos.cs, preserving the API
  contract the frontend expects.

Build clean; backend suite 135/135 green.

JobTrackerApi/Program.cs

@@ -112,6 +112,7 @@ builder.Services.AddCors(options =>
 
 // Add controllers
 builder.Services.AddControllers();
+builder.Services.AddOpenApi();
 var dataRoot = (builder.Configuration["Data:Root"] ?? "").Trim();
 if (string.IsNullOrWhiteSpace(dataRoot))
 {
@@ -128,6 +129,8 @@ Directory.CreateDirectory(dataProtectionKeysPath);
 builder.Services.AddDataProtection()
     .PersistKeysToFileSystem(new DirectoryInfo(dataProtectionKeysPath))
     .SetApplicationName("JobTracker");
+builder.Services.AddSingleton<IDatabaseBackupRunner, SqliteDatabaseBackupRunner>();
+builder.Services.AddHostedService<DatabaseBackupHostedService>();
 builder.Services.AddHostedService<RulesHostedService>();
 builder.Services.AddHostedService<FollowUpReminderHostedService>();
 builder.Services.AddHostedService<DailyExportHostedService>();
@@ -155,6 +158,7 @@ builder.Services.AddHttpClient("ai-service", client =>
 builder.Services.AddMemoryCache();
 builder.Services.AddScoped<AnalyticsService>();
 builder.Services.AddSingleton<ISummarizerService, SummarizerService>();
+builder.Services.AddSingleton<IJobCvMatchService, JobCvMatchService>();
 builder.Services.AddSingleton<ICvAiClassifier, CvAiClassifier>();
 builder.Services.AddSingleton<ICvAiNormalizer, CvAiNormalizer>();
 builder.Services.AddSingleton<IGoogleTokenValidator, GoogleTokenValidator>();
@@ -440,4 +444,10 @@ app.UseAuthentication();
 app.UseAuthorization();
 app.MapControllers();
 
+// API schema for tooling/docs. Dev-only: not exposed in production deployments.
+if (app.Environment.IsDevelopment())
+{
+    app.MapOpenApi().AllowAnonymous();
+}
+
 app.Run();