feat: integrate Career Workspace foundation from feature/career-workspace

Recover the F1 Career Profile foundation + AI-workspace persistence from the
unmerged feature/career-workspace branch, so Phase 2 builds on the documented,
tested target state instead of re-deriving it. Foundation only — CV Builder
commits (variants, ATS badge, rewrite diff) stay deferred per "do not build CV
Builder yet". See docs/career-workspace-branch-assessment.md.

Squashed from 3 branch commits (235e291, 5916f09, 00a035e), resolved against
main + Phase 0:

- CareerProfile + CareerProfileVersion (append-only history), dual-written from
  every profile save path via CareerProfileService. ApplicationUser.
  ProfileCvStructureJson stays authoritative; the tables mirror it. Stable item
  IDs assigned to jobs/education/certifications/projects (the prerequisite for
  future variant lineage). CvDateNormalizer for free-text -> YYYY-MM.
- InterviewPrepNote + AiWorkspaceNote: cache AI interview prep / candidate fit /
  focus plan keyed by an attachment-context signature, so they stop regenerating
  (and re-spending the provider) on every open.

Conflict resolutions (union, favouring current code + Phase 0):
- JobTrackerContext / StartupInitializationExtensions: kept Phase 0's tables and
  reconciler blocks, added the career/interview/ai-note tables (both SQLite and
  MySQL dialects).
- ProfileCvController: dropped the branch's in-file DTO records (main defines them
  in ProfileCvDtos.cs) and the LayoutFamily/AtsRating template fields (deferred
  ATS-badge work), keeping main's 7-arg CvTemplateDescriptor.
- JobApplicationsController: kept the branch's cache-check, restored main's
  AsNoTracking on the read-only user load.

Tables ship empty (verified dev); nothing to migrate.

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

JobTrackerApi.Tests/AiWorkspaceNotePersistenceTests.cs

@@ -0,0 +1,144 @@
+using System.Security.Claims;
+using JobTrackerApi.Controllers;
+using JobTrackerApi.Data;
+using JobTrackerApi.Models;
+using JobTrackerApi.Services;
+using JobTrackerApi.Tests.TestSupport;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace JobTrackerApi.Tests;
+
+// Candidate fit and focus plan share AiWorkspaceNote persistence with the same rules as
+// InterviewPrepNote: reuse across calls, regenerate on refresh, regenerate when the attachment
+// selection changes (career-workspace-implementation-roadmap.md Phase F5).
+public sealed class AiWorkspaceNotePersistenceTests
+{
+    [Fact]
+    public async Task GetCandidateFit_persists_and_reuses_the_generated_note()
+    {
+        await using var db = TestHostFactory.CreateInMemoryDb();
+        var job = await SeedJobWithCvAsync(db);
+
+        var summarizer = new Mock<ISummarizerService>();
+        var callCount = 0;
+        summarizer.Setup(x => x.SummarizeSectionAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<int>(), It.IsAny<int>()))
+            .ReturnsAsync(() => { callCount++; return $"Summary call {callCount}"; });
+
+        var controller = CreateController(db, summarizer.Object, "user-1");
+
+        var first = await controller.GetCandidateFit(job.Id, null, false, CancellationToken.None);
+        var callsAfterFirst = callCount;
+
+        var second = await controller.GetCandidateFit(job.Id, null, false, CancellationToken.None);
+
+        Assert.Equal(GetDto(first).MatchSummary, GetDto(second).MatchSummary);
+        Assert.Equal(callsAfterFirst, callCount);
+
+        var stored = Assert.Single(db.AiWorkspaceNotes.IgnoreQueryFilters().Where(x => x.JobApplicationId == job.Id && x.NoteType == "candidate-fit"));
+        Assert.NotEmpty(stored.ResultJson);
+    }
+
+    [Fact]
+    public async Task GetCandidateFit_regenerates_when_refresh_is_requested()
+    {
+        await using var db = TestHostFactory.CreateInMemoryDb();
+        var job = await SeedJobWithCvAsync(db);
+
+        var summarizer = new Mock<ISummarizerService>();
+        var callCount = 0;
+        summarizer.Setup(x => x.SummarizeSectionAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<int>(), It.IsAny<int>()))
+            .ReturnsAsync(() => { callCount++; return $"Summary call {callCount}"; });
+
+        var controller = CreateController(db, summarizer.Object, "user-1");
+
+        await controller.GetCandidateFit(job.Id, null, false, CancellationToken.None);
+        var callsAfterFirst = callCount;
+
+        var refreshed = await controller.GetCandidateFit(job.Id, null, true, CancellationToken.None);
+
+        Assert.True(callCount > callsAfterFirst);
+        Assert.NotNull(GetDto(refreshed).MatchSummary);
+    }
+
+    [Fact]
+    public async Task GetFocusPlan_persists_and_reuses_the_generated_note()
+    {
+        await using var db = TestHostFactory.CreateInMemoryDb();
+        var job = await SeedJobWithCvAsync(db);
+
+        var summarizer = new Mock<ISummarizerService>();
+        var callCount = 0;
+        summarizer.Setup(x => x.SummarizeSectionAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<int>(), It.IsAny<int>()))
+            .ReturnsAsync(() => { callCount++; return $"Text {callCount}"; });
+
+        var controller = CreateController(db, summarizer.Object, "user-1");
+
+        await controller.GetFocusPlan(job.Id, null, false, CancellationToken.None);
+        var callsAfterFirst = callCount;
+
+        await controller.GetFocusPlan(job.Id, null, false, CancellationToken.None);
+
+        Assert.Equal(callsAfterFirst, callCount);
+
+        var stored = Assert.Single(db.AiWorkspaceNotes.IgnoreQueryFilters().Where(x => x.JobApplicationId == job.Id && x.NoteType == "focus-plan"));
+        Assert.NotEmpty(stored.ResultJson);
+    }
+
+    private static CandidateFitDto GetDto(ActionResult<CandidateFitDto> result)
+        => (CandidateFitDto)Assert.IsType<OkObjectResult>(result.Result).Value!;
+
+    private static async Task<JobApplication> SeedJobWithCvAsync(JobTrackerContext db)
+    {
+        var company = new Company { Name = "Acme", OwnerUserId = "user-1" };
+        db.Companies.Add(company);
+        db.Users.Add(new ApplicationUser
+        {
+            Id = "user-1",
+            UserName = "user@example.test",
+            Email = "user@example.test",
+            ProfileCvText = "Built .NET APIs and led backend delivery with SQL and Docker.",
+            ProfileCvStructureJson = "[]",
+        });
+        await db.SaveChangesAsync();
+
+        var job = new JobApplication
+        {
+            JobTitle = "Backend Developer",
+            CompanyId = company.Id,
+            OwnerUserId = "user-1",
+            Description = "Needs .NET, SQL, and Docker experience.",
+        };
+        db.JobApplications.Add(job);
+        await db.SaveChangesAsync();
+        return job;
+    }
+
+    private static JobApplicationsController CreateController(JobTrackerContext db, ISummarizerService summarizer, string userId)
+    {
+        var user = db.Users.AsNoTracking().FirstOrDefault(x => x.Id == userId);
+        var controller = new JobApplicationsController(
+            db,
+            summarizer,
+            Mock.Of<IAppEmailSender>(),
+            TestHostFactory.CreateUserManager(user).Object,
+            NullLogger<JobApplicationsController>.Instance,
+            Mock.Of<ICvTemplateRenderer>(),
+            Mock.Of<ICvPdfExporter>());
+        controller.ControllerContext = new ControllerContext
+        {
+            HttpContext = new DefaultHttpContext
+            {
+                User = new ClaimsPrincipal(new ClaimsIdentity(new[]
+                {
+                    new Claim(ClaimTypes.NameIdentifier, userId)
+                }, "test"))
+            }
+        };
+        return controller;
+    }
+}