feat(ai): pgvector embedding infrastructure (#19)

docker-compose.yml

@@ -1,6 +1,8 @@
 services:
   postgres:
-    image: postgres:16-alpine
+    # pgvector-enabled Postgres 16 (semantic search). Drop-in for postgres:16 data;
+    # the 'vector' extension is created by the AddEmbeddingColumn migration.
+    image: pgvector/pgvector:pg16
     environment:
       POSTGRES_DB: inboxintel
       POSTGRES_USER: inboxintel

src/InboxIntel.Domain/Entities/Email.cs

@@ -54,6 +54,13 @@ public class Email : AuditableEntity
     /// </summary>
     public NpgsqlTypes.NpgsqlTsVector? SearchVector { get; set; }
 
+    /// <summary>
+    /// Semantic-search embedding (pgvector, 768-dim for nomic-embed-text). Populated by the
+    /// embedding backfill worker when AI is enabled; null otherwise (search falls back to
+    /// lexical). Nullable so the InMemory test provider and AI-off deployments work unchanged.
+    /// </summary>
+    public Pgvector.Vector? Embedding { get; set; }
+
     public ICollection<EmailLabel> EmailLabels { get; set; } = new List<EmailLabel>();
     public ICollection<Attachment> Attachments { get; set; } = new List<Attachment>();
 }

src/InboxIntel.Domain/InboxIntel.Domain.csproj

@@ -4,7 +4,9 @@
     <AssemblyName>InboxIntel.Domain</AssemblyName>
   </PropertyGroup>
   <ItemGroup>
-    <!-- NpgsqlTypes.NpgsqlTsVector is used on the Email entity for FTS mapping. -->
+    <!-- NpgsqlTypes.NpgsqlTsVector (FTS) and Pgvector.Vector (semantic search) are used as
+         column types on the Email entity — same pragmatic precedent for both. -->
     <PackageReference Include="Npgsql" Version="8.0.3" />
+    <PackageReference Include="Pgvector" Version="0.2.0" />
   </ItemGroup>
 </Project>

src/InboxIntel.Infrastructure/DependencyInjection.cs

@@ -21,10 +21,11 @@ public static class DependencyInjection
 {
     public static IServiceCollection AddInfrastructure(this IServiceCollection services, IConfiguration config)
     {
-        // EF Core / PostgreSQL
+        // EF Core / PostgreSQL. UseVector() enables pgvector mapping for the semantic-search
+        // embedding column (requires the 'vector' extension — added by the AddEmbeddingColumn migration).
         services.AddDbContext<AppDbContext>(opt =>
             opt.UseNpgsql(config.GetConnectionString("Postgres"),
-                npg => npg.MigrationsAssembly(typeof(AppDbContext).Assembly.FullName)));
+                npg => npg.MigrationsAssembly(typeof(AppDbContext).Assembly.FullName).UseVector()));
         services.AddScoped<IAppDbContext>(sp => sp.GetRequiredService<AppDbContext>());
 
         // Options

src/InboxIntel.Infrastructure/InboxIntel.Infrastructure.csproj

@@ -15,6 +15,7 @@
     <PackageReference Include="Microsoft.AspNetCore.DataProtection" Version="8.0.7" />
     <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="8.0.0" />
+    <PackageReference Include="Pgvector.EntityFrameworkCore" Version="0.2.0" />
     <PackageReference Include="Polly" Version="8.4.1" />
     <PackageReference Include="QuestPDF" Version="2024.7.0" />
     <PackageReference Include="CsvHelper" Version="33.0.1" />

src/InboxIntel.Infrastructure/Migrations/20260702002304_AddEmbeddingColumn.Designer.cs

@@ -0,0 +1,768 @@
+// <auto-generated />
+using System;
+using InboxIntel.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using NpgsqlTypes;
+using Pgvector;
+
+#nullable disable
+
+namespace InboxIntel.Infrastructure.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260702002304_AddEmbeddingColumn")]
+    partial class AddEmbeddingColumn
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.4")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "pg_trgm");
+            NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "vector");
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.AnalyticsAggregate", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateOnly>("Day")
+                        .HasColumnType("date");
+
+                    b.Property<string>("HourHistogramJson")
+                        .HasColumnType("text");
+
+                    b.Property<int>("NewsletterCount")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("TotalReceived")
+                        .HasColumnType("integer");
+
+                    b.Property<long>("TotalSizeBytes")
+                        .HasColumnType("bigint");
+
+                    b.Property<int>("TotalUnread")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.Property<int>("WithAttachments")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId", "Day")
+                        .IsUnique();
+
+                    b.ToTable("analytics_aggregates", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Attachment", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("EmailId")
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("FileName")
+                        .IsRequired()
+                        .HasMaxLength(512)
+                        .HasColumnType("character varying(512)");
+
+                    b.Property<string>("GmailAttachmentId")
+                        .HasColumnType("text");
+
+                    b.Property<string>("MimeType")
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<long>("SizeBytes")
+                        .HasColumnType("bigint");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("EmailId");
+
+                    b.HasIndex("UserId", "MimeType");
+
+                    b.ToTable("attachments", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Email", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("BodyText")
+                        .HasColumnType("text");
+
+                    b.Property<int>("Category")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Vector>("Embedding")
+                        .HasColumnType("vector(768)");
+
+                    b.Property<string>("GmailMessageId")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<bool>("HasAttachments")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("HasListUnsubscribe")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("IsImportant")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("IsInInbox")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("IsStarred")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("IsTrashed")
+                        .HasColumnType("boolean");
+
+                    b.Property<bool>("IsUnread")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("ListUnsubscribeRaw")
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)");
+
+                    b.Property<DateTimeOffset?>("ReceivedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<NpgsqlTsVector>("SearchVector")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("tsvector")
+                        .HasComputedColumnSql("setweight(to_tsvector('english', coalesce(\"Subject\",'')), 'A') || setweight(to_tsvector('english', coalesce(\"BodyText\",'')), 'B')", true);
+
+                    b.Property<Guid>("SenderId")
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("SentAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long>("SizeEstimateBytes")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("Snippet")
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)");
+
+                    b.Property<string>("Subject")
+                        .HasMaxLength(1024)
+                        .HasColumnType("character varying(1024)");
+
+                    b.Property<bool>("SupportsOneClickUnsubscribe")
+                        .HasColumnType("boolean");
+
+                    b.Property<Guid>("ThreadId")
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Embedding");
+
+                    NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("Embedding"), "hnsw");
+                    NpgsqlIndexBuilderExtensions.HasOperators(b.HasIndex("Embedding"), new[] { "vector_cosine_ops" });
+
+                    b.HasIndex("SearchVector");
+
+                    NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("SearchVector"), "GIN");
+
+                    b.HasIndex("SenderId");
+
+                    b.HasIndex("ThreadId");
+
+                    b.HasIndex("UserId", "Category");
+
+                    b.HasIndex("UserId", "GmailMessageId")
+                        .IsUnique();
+
+                    b.HasIndex("UserId", "IsInInbox");
+
+                    b.HasIndex("UserId", "IsUnread");
+
+                    b.HasIndex("UserId", "SenderId");
+
+                    b.HasIndex("UserId", "SentAtUtc");
+
+                    b.ToTable("emails", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.EmailLabel", b =>
+                {
+                    b.Property<Guid>("EmailId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Guid>("LabelId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("EmailId", "LabelId");
+
+                    b.HasIndex("LabelId");
+
+                    b.ToTable("email_labels", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Label", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("ColorHex")
+                        .HasColumnType("text");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("GmailLabelId")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<string>("Type")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId", "GmailLabelId")
+                        .IsUnique();
+
+                    b.ToTable("labels", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.MailDomain", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("EmailCount")
+                        .HasColumnType("integer");
+
+                    b.Property<bool>("IsBulkSender")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Name");
+
+                    NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("Name"), "gin");
+                    NpgsqlIndexBuilderExtensions.HasOperators(b.HasIndex("Name"), new[] { "gin_trgm_ops" });
+
+                    b.HasIndex("UserId", "Name")
+                        .IsUnique();
+
+                    b.ToTable("domains", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.MailThread", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTimeOffset?>("FirstMessageUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("GmailThreadId")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<DateTimeOffset?>("LastMessageUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("MessageCount")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("Snippet")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Subject")
+                        .HasMaxLength(1024)
+                        .HasColumnType("character varying(1024)");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId", "GmailThreadId")
+                        .IsUnique();
+
+                    b.ToTable("threads", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Sender", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<string>("Address")
+                        .IsRequired()
+                        .HasMaxLength(320)
+                        .HasColumnType("character varying(320)");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("DisplayName")
+                        .HasMaxLength(255)
+                        .HasColumnType("character varying(255)");
+
+                    b.Property<Guid>("DomainId")
+                        .HasColumnType("uuid");
+
+                    b.Property<int>("EmailCount")
+                        .HasColumnType("integer");
+
+                    b.Property<bool>("HasUnsubscribe")
+                        .HasColumnType("boolean");
+
+                    b.Property<DateTimeOffset?>("LastReceivedUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<long>("TotalSizeBytes")
+                        .HasColumnType("bigint");
+
+                    b.Property<int>("UnreadCount")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Address");
+
+                    NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("Address"), "gin");
+                    NpgsqlIndexBuilderExtensions.HasOperators(b.HasIndex("Address"), new[] { "gin_trgm_ops" });
+
+                    b.HasIndex("DisplayName");
+
+                    NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("DisplayName"), "gin");
+                    NpgsqlIndexBuilderExtensions.HasOperators(b.HasIndex("DisplayName"), new[] { "gin_trgm_ops" });
+
+                    b.HasIndex("DomainId");
+
+                    b.HasIndex("UserId", "Address")
+                        .IsUnique();
+
+                    b.HasIndex("UserId", "EmailCount");
+
+                    b.ToTable("senders", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.SyncState", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset?>("CompletedUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("ConsecutiveFailures")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("LastError")
+                        .HasMaxLength(4000)
+                        .HasColumnType("character varying(4000)");
+
+                    b.Property<string>("LastHistoryId")
+                        .HasColumnType("text");
+
+                    b.Property<DateTimeOffset?>("LastSuccessfulSyncUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("LastSyncType")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("MessagesProcessed")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("ResumePageToken")
+                        .HasColumnType("text");
+
+                    b.Property<DateTimeOffset?>("StartedUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("TotalMessagesEstimate")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId")
+                        .IsUnique();
+
+                    b.ToTable("sync_states", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.UnsubscribeItem", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<double>("Confidence")
+                        .HasColumnType("double precision");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("EmailCount")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset?>("LastAttemptUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("Method")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("ResultMessage")
+                        .HasColumnType("text");
+
+                    b.Property<Guid>("SenderId")
+                        .HasColumnType("uuid");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("UnsubscribeTarget")
+                        .HasMaxLength(2048)
+                        .HasColumnType("character varying(2048)");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SenderId");
+
+                    b.HasIndex("UserId", "SenderId")
+                        .IsUnique();
+
+                    b.ToTable("unsubscribe_items", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.User", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset?>("AccessTokenExpiresAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<bool>("DigestEnabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("DisplayName")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasMaxLength(320)
+                        .HasColumnType("character varying(320)");
+
+                    b.Property<byte[]>("EncryptedRefreshToken")
+                        .HasColumnType("bytea");
+
+                    b.Property<string>("GoogleSubjectId")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<DateTimeOffset?>("LastDigestSentUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<DateTimeOffset?>("LastLoginUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("PictureUrl")
+                        .HasColumnType("text");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Email")
+                        .IsUnique();
+
+                    b.HasIndex("GoogleSubjectId")
+                        .IsUnique();
+
+                    b.ToTable("users", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.WidgetLayout", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<DateTimeOffset>("CreatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("H")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("SettingsJson")
+                        .HasColumnType("text");
+
+                    b.Property<int>("SortOrder")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTimeOffset?>("UpdatedAtUtc")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("uuid");
+
+                    b.Property<bool>("Visible")
+                        .HasColumnType("boolean");
+
+                    b.Property<int>("W")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("WidgetKey")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("character varying(64)");
+
+                    b.Property<int>("X")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("Y")
+                        .HasColumnType("integer");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId", "WidgetKey")
+                        .IsUnique();
+
+                    b.ToTable("widget_layouts", (string)null);
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Attachment", b =>
+                {
+                    b.HasOne("InboxIntel.Domain.Entities.Email", "Email")
+                        .WithMany("Attachments")
+                        .HasForeignKey("EmailId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Email");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Email", b =>
+                {
+                    b.HasOne("InboxIntel.Domain.Entities.Sender", "Sender")
+                        .WithMany("Emails")
+                        .HasForeignKey("SenderId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.HasOne("InboxIntel.Domain.Entities.MailThread", "Thread")
+                        .WithMany("Emails")
+                        .HasForeignKey("ThreadId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("InboxIntel.Domain.Entities.User", null)
+                        .WithMany("Emails")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Sender");
+
+                    b.Navigation("Thread");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.EmailLabel", b =>
+                {
+                    b.HasOne("InboxIntel.Domain.Entities.Email", "Email")
+                        .WithMany("EmailLabels")
+                        .HasForeignKey("EmailId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("InboxIntel.Domain.Entities.Label", "Label")
+                        .WithMany("EmailLabels")
+                        .HasForeignKey("LabelId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Email");
+
+                    b.Navigation("Label");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Sender", b =>
+                {
+                    b.HasOne("InboxIntel.Domain.Entities.MailDomain", "Domain")
+                        .WithMany("Senders")
+                        .HasForeignKey("DomainId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.Navigation("Domain");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.UnsubscribeItem", b =>
+                {
+                    b.HasOne("InboxIntel.Domain.Entities.Sender", "Sender")
+                        .WithMany()
+                        .HasForeignKey("SenderId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Sender");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.WidgetLayout", b =>
+                {
+                    b.HasOne("InboxIntel.Domain.Entities.User", null)
+                        .WithMany("WidgetLayouts")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Email", b =>
+                {
+                    b.Navigation("Attachments");
+
+                    b.Navigation("EmailLabels");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Label", b =>
+                {
+                    b.Navigation("EmailLabels");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.MailDomain", b =>
+                {
+                    b.Navigation("Senders");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.MailThread", b =>
+                {
+                    b.Navigation("Emails");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.Sender", b =>
+                {
+                    b.Navigation("Emails");
+                });
+
+            modelBuilder.Entity("InboxIntel.Domain.Entities.User", b =>
+                {
+                    b.Navigation("Emails");
+
+                    b.Navigation("WidgetLayouts");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

src/InboxIntel.Infrastructure/Migrations/20260702002304_AddEmbeddingColumn.cs

@@ -0,0 +1,50 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+using Pgvector;
+
+#nullable disable
+
+namespace InboxIntel.Infrastructure.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddEmbeddingColumn : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterDatabase()
+                .Annotation("Npgsql:PostgresExtension:pg_trgm", ",,")
+                .Annotation("Npgsql:PostgresExtension:vector", ",,")
+                .OldAnnotation("Npgsql:PostgresExtension:pg_trgm", ",,");
+
+            migrationBuilder.AddColumn<Vector>(
+                name: "Embedding",
+                table: "emails",
+                type: "vector(768)",
+                nullable: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_emails_Embedding",
+                table: "emails",
+                column: "Embedding")
+                .Annotation("Npgsql:IndexMethod", "hnsw")
+                .Annotation("Npgsql:IndexOperators", new[] { "vector_cosine_ops" });
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_emails_Embedding",
+                table: "emails");
+
+            migrationBuilder.DropColumn(
+                name: "Embedding",
+                table: "emails");
+
+            migrationBuilder.AlterDatabase()
+                .Annotation("Npgsql:PostgresExtension:pg_trgm", ",,")
+                .OldAnnotation("Npgsql:PostgresExtension:pg_trgm", ",,")
+                .OldAnnotation("Npgsql:PostgresExtension:vector", ",,");
+        }
+    }
+}

src/InboxIntel.Infrastructure/Migrations/AppDbContextModelSnapshot.cs

@@ -6,6 +6,7 @@ using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
 using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
 using NpgsqlTypes;
+using Pgvector;
 
 #nullable disable
 
@@ -22,6 +23,7 @@ namespace InboxIntel.Infrastructure.Migrations
                 .HasAnnotation("Relational:MaxIdentifierLength", 63);
 
             NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "pg_trgm");
+            NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "vector");
             NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
 
             modelBuilder.Entity("InboxIntel.Domain.Entities.AnalyticsAggregate", b =>
@@ -125,6 +127,9 @@ namespace InboxIntel.Infrastructure.Migrations
                     b.Property<DateTimeOffset>("CreatedAtUtc")
                         .HasColumnType("timestamp with time zone");
 
+                    b.Property<Vector>("Embedding")
+                        .HasColumnType("vector(768)");
+
                     b.Property<string>("GmailMessageId")
                         .IsRequired()
                         .HasMaxLength(64)
@@ -194,6 +199,11 @@ namespace InboxIntel.Infrastructure.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("Embedding");
+
+                    NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("Embedding"), "hnsw");
+                    NpgsqlIndexBuilderExtensions.HasOperators(b.HasIndex("Embedding"), new[] { "vector_cosine_ops" });
+
                     b.HasIndex("SearchVector");
 
                     NpgsqlIndexBuilderExtensions.HasMethod(b.HasIndex("SearchVector"), "GIN");

src/InboxIntel.Infrastructure/Persistence/AppDbContext.cs

@@ -85,10 +85,18 @@ public class AppDbContext : DbContext, IAppDbContext
                 .HasMethod("gin").HasOperators("gin_trgm_ops");
             modelBuilder.Entity<MailDomain>().HasIndex(d => d.Name)
                 .HasMethod("gin").HasOperators("gin_trgm_ops");
+
+            // pgvector: 768-dim embedding for semantic search, with an HNSW cosine index.
+            // Populated by the embedding backfill worker when AI is enabled; null otherwise.
+            modelBuilder.HasPostgresExtension("vector");
+            modelBuilder.Entity<Email>().Property(e => e.Embedding).HasColumnType("vector(768)");
+            modelBuilder.Entity<Email>().HasIndex(e => e.Embedding)
+                .HasMethod("hnsw").HasOperators("vector_cosine_ops");
         }
         else
         {
             modelBuilder.Entity<Email>().Ignore(e => e.SearchVector);
+            modelBuilder.Entity<Email>().Ignore(e => e.Embedding);
         }
 
         base.OnModelCreating(modelBuilder);

src/InboxIntel.Infrastructure/Persistence/AppDbContextFactory.cs

@@ -15,7 +15,7 @@ public class AppDbContextFactory : IDesignTimeDbContextFactory<AppDbContext>
         var conn = Environment.GetEnvironmentVariable("EF_CONNECTION")
                    ?? "Host=localhost;Port=5432;Database=inboxintel;Username=inboxintel;Password=inboxintel";
         var options = new DbContextOptionsBuilder<AppDbContext>()
-            .UseNpgsql(conn)
+            .UseNpgsql(conn, o => o.UseVector())
             .Options;
         return new AppDbContext(options);
     }