feat(cv-search-data): add JobProviders table to cvSearch schema

New JobProviderEntity persists provider config (name, URL template,
link filter, initial keywords, max results, display order) in the DB
instead of appsettings. Migration seeds three disabled defaults:
ejobs.ro, bestjobs.eu, and linkedin.com.

Closes #35

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Apis/cv-search-data/Migrations/CvSearchDbContextModelSnapshot.cs

@@ -1,4 +1,4 @@
-// <auto-generated />
+// <auto-generated />
 using System;
 using CvSearch.Data;
 using Microsoft.EntityFrameworkCore;
@@ -23,6 +23,54 @@ namespace CvSearch.Data.Migrations
 
             SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
 
+            modelBuilder.Entity("CvSearch.Data.Entities.JobProviderEntity", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<int>("DisplayOrder")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int")
+                        .HasDefaultValue(0);
+
+                    b.Property<bool>("Enabled")
+                        .HasColumnType("bit");
+
+                    b.Property<string>("InitialKeywordsJson")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(2000)
+                        .HasColumnType("nvarchar(2000)")
+                        .HasDefaultValue("[]");
+
+                    b.Property<string>("JobLinkContains")
+                        .IsRequired()
+                        .HasMaxLength(256)
+                        .HasColumnType("nvarchar(256)");
+
+                    b.Property<int>("MaxResults")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int")
+                        .HasDefaultValue(20);
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(128)
+                        .HasColumnType("nvarchar(128)");
+
+                    b.Property<string>("SearchUrlTemplate")
+                        .IsRequired()
+                        .HasMaxLength(1024)
+                        .HasColumnType("nvarchar(1024)");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("JobProviders", "cvSearch");
+                });
+
             modelBuilder.Entity("CvSearch.Data.Entities.JobSearchResultEntity", b =>
                 {
                     b.Property<string>("Id")