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  independent fix is superseded (my branch predated e352aae, which is why the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/Services/AnalyticsService.cs

@@ -64,6 +64,7 @@ namespace JobTrackerApi.Services
                 .Where(j => !j.IsDeleted)
                 .Select(j => new
                 {
+                    j.Id,
                     j.Status,
                     j.ResponseReceived,
                     j.ResponseDate,
@@ -74,16 +75,14 @@ namespace JobTrackerApi.Services
                 })
                 .ToListAsync(cancellationToken);
 
-            var funnelMap = new Dictionary<string, int>
-            {
-                ["Applied"] = activeJobs.Count(j => string.Equals(j.Status, "Applied", StringComparison.OrdinalIgnoreCase)),
-                ["Interview"] = activeJobs.Count(j => string.Equals(j.Status, "Interview", StringComparison.OrdinalIgnoreCase) || string.Equals(j.Status, "Interviewing", StringComparison.OrdinalIgnoreCase)),
-                ["Offer"] = activeJobs.Count(j => string.Equals(j.Status, "Offer", StringComparison.OrdinalIgnoreCase)),
-                ["Rejected"] = activeJobs.Count(j => string.Equals(j.Status, "Rejected", StringComparison.OrdinalIgnoreCase)),
-                ["Ghosted"] = activeJobs.Count(j => string.Equals(j.Status, "Ghosted", StringComparison.OrdinalIgnoreCase)),
-            };
-
-            var funnel = funnelMap.Select(x => new FunnelStagePoint(x.Key, x.Value)).ToList();
+            // Funnel = distribution across canonical stages, driven by the pipeline (one source
+            // of truth, so it includes every stage and normalizes legacy spellings).
+            var normalizedByStage = activeJobs
+                .GroupBy(j => JobPipeline.Normalize(j.Status))
+                .ToDictionary(g => g.Key, g => g.Count());
+            var funnel = JobPipeline.Stages
+                .Select(stage => new FunnelStagePoint(stage.Key, normalizedByStage.TryGetValue(stage.Key, out var c) ? c : 0))
+                .ToList();
 
             var responseRateBySource = activeJobs
                 .GroupBy(j => string.IsNullOrWhiteSpace(j.CompanySource) ? "Unknown source" : j.CompanySource!.Trim())
@@ -127,13 +126,46 @@ namespace JobTrackerApi.Services
                     : Math.Round(responseDays[mid], 1);
             }
 
+            // Time-in-stage: for each active job, when did it enter its current stage? Use the most
+            // recent StatusChanged event into that stage, else its applied date.
+            var activeIds = activeJobs.Select(j => j.Id).ToList();
+            var statusChanges = await _db.JobEvents
+                .AsNoTracking()
+                .Where(e => e.Type == "StatusChanged" && activeIds.Contains(e.JobApplicationId))
+                .Select(e => new { e.JobApplicationId, e.NewValue, e.At })
+                .ToListAsync(cancellationToken);
+
+            var lastEntryByJob = statusChanges
+                .GroupBy(e => e.JobApplicationId)
+                .ToDictionary(g => g.Key, g => g.ToList());
+
+            var occupancy = activeJobs.Select(job =>
+            {
+                var current = JobPipeline.Normalize(job.Status);
+                DateTime enteredAt = job.DateApplied;
+                if (lastEntryByJob.TryGetValue(job.Id, out var changes))
+                {
+                    var lastIntoCurrent = changes
+                        .Where(e => JobPipeline.Normalize(e.NewValue) == current)
+                        .OrderByDescending(e => e.At)
+                        .FirstOrDefault();
+                    if (lastIntoCurrent is not null) enteredAt = lastIntoCurrent.At;
+                }
+                return new StageOccupancy(current, enteredAt.ToUniversalTime());
+            });
+
+            var timeInStage = StageAnalytics.TimeInStage(occupancy, DateTime.UtcNow)
+                .Select(p => new StageDurationDto(p.Stage, p.MedianDays, p.Count))
+                .ToList();
+
             return new AnalyticsOverviewDto(
                 Funnel: funnel,
                 ResponseRateBySource: responseRateBySource,
                 TopCompanies: topCompanies,
                 MedianDaysToFirstResponse: medianDays,
                 TotalResponses: activeJobs.Count(j => j.ResponseReceived || j.ResponseDate is not null),
-                TotalActive: activeJobs.Count
+                TotalActive: activeJobs.Count,
+                TimeInStage: timeInStage
             );
         }
     }