feat: DB-backed localized templates + language-aware emails

- New Apis/myai-models project: MyAiDbContext (schema myAi), TemplateEntity,
  ITemplateService, DbTemplateService with 10-min in-memory cache
- Seeds EN+RO variants for all user-facing templates (match email, job search
  results email, HTML status pages, AI system prompt)
- Match result email now sent in user's UI language (en/ro)
- Job search results email now respects session language
- Language propagates: MatchJobRequest -> token -> session -> email
- Add Language column to JobSearchTokens and JobSearchSessions (default 'en')
- All three Dockerfiles updated to include myai-models in build context

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

Apis/myai-models/Data/Entities/TemplateEntity.cs

@@ -0,0 +1,10 @@
+namespace MyAi.Models.Data.Entities;
+
+public sealed class TemplateEntity
+{
+    public string Key { get; set; } = string.Empty;
+    public string Language { get; set; } = string.Empty;
+    public string Value { get; set; } = string.Empty;
+    public string Description { get; set; } = string.Empty;
+    public DateTime UpdatedAt { get; set; }
+}

Apis/myai-models/Data/MyAiDbContext.cs

@@ -0,0 +1,30 @@
+using MyAi.Models.Data.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace MyAi.Models.Data;
+
+public sealed class MyAiDbContext : DbContext
+{
+    public const string SchemaName = "myAi";
+    public const string MigrationTableName = "_MyAiMigrations";
+
+    public MyAiDbContext(DbContextOptions<MyAiDbContext> options) : base(options) { }
+
+    public DbSet<TemplateEntity> Templates => Set<TemplateEntity>();
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        modelBuilder.HasDefaultSchema(SchemaName);
+
+        modelBuilder.Entity<TemplateEntity>(entity =>
+        {
+            entity.ToTable("Templates");
+            entity.HasKey(x => new { x.Key, x.Language });
+            entity.Property(x => x.Key).HasMaxLength(128);
+            entity.Property(x => x.Language).HasMaxLength(8);
+            entity.Property(x => x.Value).IsRequired();
+            entity.Property(x => x.Description).HasMaxLength(500).HasDefaultValue(string.Empty);
+            entity.Property(x => x.UpdatedAt).HasDefaultValueSql("SYSUTCDATETIME()");
+        });
+    }
+}