fix: close release preflight gaps

Route public health checks to the API, backfill and synchronize job opportunities, stabilize SPA smoke tests, and document operator-only production steps.

JobTrackerApi/Controllers/JobApplicationsController.cs

@@ -702,27 +702,6 @@ Canonical profile:
             return Ok(dtos);
         }
 
-        private static void SyncOpportunity(JobApplication application, Job opportunity)
-        {
-            opportunity.OwnerUserId = application.OwnerUserId;
-            opportunity.CompanyId = application.CompanyId;
-            opportunity.JobTitle = application.JobTitle;
-            opportunity.Location = application.Location;
-            opportunity.JobUrl = application.JobUrl;
-            opportunity.Description = application.Description;
-            opportunity.TranslatedDescription = application.TranslatedDescription;
-            opportunity.DescriptionLanguage = application.DescriptionLanguage;
-            opportunity.ShortSummary = application.ShortSummary;
-            opportunity.Tags = application.Tags;
-            opportunity.Deadline = application.Deadline;
-            opportunity.Salary = application.Salary;
-            opportunity.SalaryMin = application.SalaryMin;
-            opportunity.SalaryMax = application.SalaryMax;
-            opportunity.SalaryCurrency = application.SalaryCurrency;
-            opportunity.SalaryPeriod = application.SalaryPeriod;
-            opportunity.SavedAt = application.SavedAt;
-        }
-
         private static (decimal? Min, decimal? Max, string? Currency, string? Period) NormalizeSalary(
             decimal? min, decimal? max, string? currency, string? period)
         {
@@ -782,7 +761,7 @@ Canonical profile:
             if (source?.Length > 32) source = source[..32];
             var countryCode = string.IsNullOrWhiteSpace(request.CountryCode) ? null : request.CountryCode.Trim().ToUpperInvariant();
             if (countryCode?.Length != 2) countryCode = null;
-            job.Job = new Job { Source = source, CountryCode = countryCode };
+            job.Job = JobOpportunitySync.Create(job, source, countryCode);
 
             // A job created straight into a pre-application stage has not been applied to, so it
             // must not carry an applied date. SyncAppliedDate also covers the reverse: a create
@@ -803,7 +782,7 @@ Canonical profile:
                 // ignore summarizer failures at create time
             }
 
-            SyncOpportunity(job, job.Job);
+            JobOpportunitySync.Apply(job, job.Job);
             _db.JobApplications.Add(job);
             await _db.SaveChangesAsync(cancellationToken);
 
@@ -879,7 +858,7 @@ Canonical profile:
             // Records StatusChanged plus any lifecycle event the transition implies.
             JobLifecycleEvents.RecordStatusChange(_db, job, oldStatus, request.StatusChangedAt ?? DateTime.Now);
 
-            if (job.Job is not null) SyncOpportunity(job, job.Job);
+            if (job.Job is not null) JobOpportunitySync.Apply(job, job.Job);
             await _db.SaveChangesAsync(cancellationToken);
             return NoContent();
         }