feat(workspace): Application Workspace foundation (Phase 5 milestone 1)

Every JobApplication gets a dedicated workspace at /applications/{id} — a
surface, not a new data store. It owns no data and duplicates none: CV comes
from the Phase 4 CvVariant lens, analysis/match/interview from the existing
AiWorkspacePanel, documents from Attachments, communication from
Correspondence, activity from JobEvent, stage semantics from JobPipeline. No
career data is copied and nothing here writes.

- GET /api/jobapplications/{id}/workspace: one aggregate read (role, company,
  stage, dates, attached CV variant, cover letter, documents, AI history,
  recent activity) replacing the page fanning out across endpoints
- Next recommended action: ordered rules answering "what do I do next?", the
  core product principle for this phase
- ApplicationWorkspacePage: left nav + linkable ?section=, reusing the existing
  component for each domain; later-milestone sections say so rather than faking
- Entry point from the job dialog via an optional onOpenWorkspace callback —
  the dialog must not depend on router context (it is mounted without a
  <Router> in several suites), so the caller owns navigation
- 8 backend tests (aggregate, CV variant surfacing, counts, activity ordering,
  next-step rules, tenant scoping)

Local: 314 backend, 88/88 frontend (31 suites), tsc clean, production build ok.

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

JobTrackerApi.Tests/ApplicationWorkspaceTests.cs

@@ -0,0 +1,181 @@
+using JobTrackerApi.Data;
+using JobTrackerApi.Models;
+using JobTrackerApi.Services;
+using Microsoft.EntityFrameworkCore;
+using Moq;
+using Xunit;
+
+namespace JobTrackerApi.Tests;
+
+public sealed class ApplicationWorkspaceTests
+{
+    private static (JobTrackerContext db, ApplicationWorkspaceService svc) New(string userId)
+    {
+        var options = new DbContextOptionsBuilder<JobTrackerContext>()
+            .UseInMemoryDatabase(Guid.NewGuid().ToString()).Options;
+        var currentUser = new Mock<ICurrentUserService>();
+        currentUser.SetupGet(s => s.UserId).Returns(userId);
+        var db = new JobTrackerContext(options, currentUser.Object);
+        return (db, new ApplicationWorkspaceService(db));
+    }
+
+    private static async Task<JobApplication> SeedAsync(JobTrackerContext db, string owner, Action<JobApplication>? tweak = null)
+    {
+        var company = new Company { OwnerUserId = owner, Name = "Acme" };
+        db.Companies.Add(company);
+        await db.SaveChangesAsync();
+        var job = new JobApplication
+        {
+            OwnerUserId = owner,
+            CompanyId = company.Id,
+            JobTitle = "Backend Developer",
+            Status = "Applied",
+            Location = "Oslo",
+            Description = "Needs .NET and SQL.",
+            DateApplied = DateTime.UtcNow.AddDays(-3),
+        };
+        tweak?.Invoke(job);
+        db.JobApplications.Add(job);
+        await db.SaveChangesAsync();
+        return job;
+    }
+
+    [Fact]
+    public async Task Overview_aggregates_the_application_without_copying_career_data()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1");
+
+        var o = await svc.GetOverviewAsync("user-1", job.Id, default);
+
+        Assert.NotNull(o);
+        Assert.Equal("Backend Developer", o!.JobTitle);
+        Assert.Equal("Acme", o.Company);
+        Assert.Equal("Oslo", o.Location);
+        Assert.True(o.HasJobDescription);
+        Assert.Null(o.Cv.VariantId);          // no variant attached yet
+        Assert.False(o.HasCoverLetter);
+        Assert.Equal(0, o.DocumentCount);
+    }
+
+    [Fact]
+    public async Task Overview_surfaces_the_attached_cv_variant()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1");
+        db.CvVariants.Add(new CvVariant
+        {
+            OwnerUserId = "user-1",
+            JobApplicationId = job.Id,
+            PublicSlug = Guid.NewGuid().ToString("N"),
+            Name = "Backend CV",
+            SettingsJson = CvVariantSettingsJson.Serialize(new CvVariantSettings { ThemeId = "nordic" }),
+            UpdatedAtUtc = DateTimeOffset.UtcNow,
+        });
+        await db.SaveChangesAsync();
+
+        var o = await svc.GetOverviewAsync("user-1", job.Id, default);
+
+        Assert.Equal("Backend CV", o!.Cv.VariantName);
+        Assert.Equal("nordic", o.Cv.ThemeId);
+    }
+
+    [Fact]
+    public async Task Overview_counts_documents_and_ai_history()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1");
+        db.Attachments.Add(new Attachment { JobApplicationId = job.Id, FileName = "cert.pdf", FilePath = "/tmp/a.pdf", FileType = "PDF" });
+        db.AiInteractions.Add(new AiInteraction
+        {
+            OwnerUserId = "user-1", JobApplicationId = job.Id, Module = "job-analysis",
+            Title = "Job analysis", Provider = "p", ResultJson = "{}", CreatedAtUtc = DateTimeOffset.UtcNow,
+        });
+        await db.SaveChangesAsync();
+
+        var o = await svc.GetOverviewAsync("user-1", job.Id, default);
+
+        Assert.Equal(1, o!.DocumentCount);
+        Assert.Equal(1, o.AiInteractionCount);
+        Assert.NotNull(o.LastAiAtUtc);
+    }
+
+    [Fact]
+    public async Task Overview_returns_recent_activity_newest_first()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1");
+        db.JobEvents.Add(new JobEvent { JobApplicationId = job.Id, Type = "Created", At = DateTime.Now.AddDays(-2) });
+        db.JobEvents.Add(new JobEvent { JobApplicationId = job.Id, Type = "StatusChanged", NewValue = "Applied", At = DateTime.Now });
+        await db.SaveChangesAsync();
+
+        var o = await svc.GetOverviewAsync("user-1", job.Id, default);
+
+        Assert.Equal(new[] { "StatusChanged", "Created" }, o!.RecentActivity.Select(a => a.Type));
+    }
+
+    // --- next recommended action: "the user should never ask what to do next" ---
+
+    [Fact]
+    public async Task Next_step_asks_for_the_advert_when_there_is_no_description()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1", j => j.Description = null);
+
+        var o = await svc.GetOverviewAsync("user-1", job.Id, default);
+
+        Assert.Equal("add-job-details", o!.NextStep!.Key);
+    }
+
+    [Fact]
+    public async Task Next_step_walks_cv_then_cover_letter_then_documents()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1");
+
+        Assert.Equal("prepare-cv", (await svc.GetOverviewAsync("user-1", job.Id, default))!.NextStep!.Key);
+
+        job.TailoredCvText = "tailored";
+        await db.SaveChangesAsync();
+        Assert.Equal("write-cover-letter", (await svc.GetOverviewAsync("user-1", job.Id, default))!.NextStep!.Key);
+
+        job.CoverLetterText = "Dear team";
+        await db.SaveChangesAsync();
+        Assert.Equal("attach-documents", (await svc.GetOverviewAsync("user-1", job.Id, default))!.NextStep!.Key);
+    }
+
+    [Fact]
+    public async Task Next_step_prioritises_interview_prep_at_the_interview_stage()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var job = await SeedAsync(db, "user-1", j =>
+        {
+            j.Status = "Interview";
+            j.TailoredCvText = "tailored";
+            j.CoverLetterText = "letter";
+        });
+        db.Attachments.Add(new Attachment { JobApplicationId = job.Id, FileName = "c.pdf", FilePath = "/tmp/c.pdf", FileType = "PDF" });
+        await db.SaveChangesAsync();
+
+        var o = await svc.GetOverviewAsync("user-1", job.Id, default);
+
+        Assert.Equal("prepare-interview", o!.NextStep!.Key);
+    }
+
+    [Fact]
+    public async Task Another_users_application_is_not_visible()
+    {
+        var (db, svc) = New("user-1");
+        await using var _ = db;
+        var other = await SeedAsync(db, "user-2");
+
+        Assert.Null(await svc.GetOverviewAsync("user-1", other.Id, default));
+    }
+}