feat(career): wire /career to the relational profile API + completeness overview

Phase 3, frontend. /career now reads and writes the master profile through the
relational source of truth instead of the legacy blob path.

- CareerProfilePage loads GET /career/profile (structured profile from the
  relational children + cvText + completeness) and saves PUT /career/profile
  ({ profile, cvText }). This keeps the relational store authoritative — the
  previous PUT /auth/profile blob write left it stale after first load.
- Added a "Profile completeness" overview (percent bar + missing sections) at the
  top of /career, from the server scorecard.
- PUT /career/profile now accepts { profile, cvText } so the single /career save
  covers both the structured profile and the raw imported text; GET returns cvText.

Tests: career-save asserts the /career/profile payload; new completeness-overview
test; controller tests updated for the request wrapper. 75/76 frontend pass (the
1 failure is the unrelated pre-existing settings-view suite); prod build clean.

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

JobTrackerApi.Tests/CareerProfileControllerTests.cs

@@ -47,7 +47,7 @@ public sealed class CareerProfileControllerTests
     {
         var (controller, _, user) = Build();
 
-        var put = await controller.Put(Sample(), CancellationToken.None);
+        var put = await controller.Put(new CareerProfileSaveRequest(Sample(), null), CancellationToken.None);
         Assert.IsType<OkObjectResult>(put.Result);
 
         // The derived blob projection is kept in sync for legacy readers.
@@ -64,7 +64,7 @@ public sealed class CareerProfileControllerTests
     public async Task Get_reports_completeness_with_missing_sections()
     {
         var (controller, _, _) = Build();
-        await controller.Put(Sample(), CancellationToken.None);   // has personal + experience + skills
+        await controller.Put(new CareerProfileSaveRequest(Sample(), null), CancellationToken.None);   // has personal + experience + skills
 
         var get = await controller.Get(CancellationToken.None);
         var dto = Assert.IsType<CareerProfileDto>(Assert.IsType<OkObjectResult>(get.Result).Value);
@@ -81,7 +81,7 @@ public sealed class CareerProfileControllerTests
         var huge = new StructuredCvProfile();
         for (var i = 0; i < 500; i++) huge.Skills.Add($"skill-{i}");
 
-        var put = await controller.Put(huge, CancellationToken.None);
+        var put = await controller.Put(new CareerProfileSaveRequest(huge, null), CancellationToken.None);
 
         Assert.IsType<BadRequestObjectResult>(put.Result);
     }
@@ -91,7 +91,7 @@ public sealed class CareerProfileControllerTests
     {
         var (controller, _, _) = Build();
 
-        var put = await controller.Put(new StructuredCvProfile(), CancellationToken.None);
+        var put = await controller.Put(new CareerProfileSaveRequest(new StructuredCvProfile(), null), CancellationToken.None);
 
         // Completeness, not validation, is what flags an incomplete profile — an empty profile saves.
         Assert.IsType<OkObjectResult>(put.Result);