fix(db): provision CV builder + AI workspace tables via the MySQL-safe reconciler

Deploy failed on prod (MariaDB) while the test job was green: backend startup
threw during Database.Migrate(), so deploy.sh's post-deploy health check exited.

Root cause: AddCvVariants/AddAiInteractions were scaffolded against SQLite, so
they bake SQLite type names into their DDL — DateTimeOffset emits `TEXT`, bool/int
emit `INTEGER`, and the PK gets no AUTO_INCREMENT. Run against MariaDB that yields
a structurally wrong table, and the composite index over a TEXT column then trips
"ERROR 1071: Specified key was too long; max key length is 3072 bytes". SQLite
accepts all of it, which is why local/container verification passed.

Fix, following the pattern already used for CareerProfiles/AiWorkspaceNotes:
- both migrations become no-ops; the three tables are reconciler-owned
- reconciler provisions them idempotently per dialect (MySQL: varchar/int
  AUTO_INCREMENT/datetime(6); SQLite: CREATE TABLE IF NOT EXISTS)
- DropMalformedMySqlTable rebuilds a half-built table left by the failed
  migration, guarded on row count so a table with ANY rows is never dropped
- bound the indexed string columns with HasMaxLength so the model matches

Verified against a real MariaDB 11 container: reproduced error 1071, then
confirmed the corrected DDL yields auto_increment PKs, varchar/datetime columns
and all previously-failing indexes. 306 backend tests green; SQLite container
starts clean.

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

Data/JobTrackerContext.cs

@@ -298,6 +298,12 @@ namespace JobTrackerApi.Data
         // owns career data. PublicSlug is globally unique so /cv/{slug} can resolve it anonymously.
         modelBuilder.Entity<CvVariant>()
             .HasQueryFilter(x => CurrentUserId != null && x.OwnerUserId == CurrentUserId);
+        // Bound the indexed string columns so Pomelo maps them to varchar, not longtext (MariaDB
+        // cannot index a TEXT/longtext column without a prefix length). Actual prod DDL is applied by
+        // the reconciler (StartupInitializationExtensions), MySQL-safe; see that file + DbContext note.
+        modelBuilder.Entity<CvVariant>().Property(x => x.OwnerUserId).HasMaxLength(255);
+        modelBuilder.Entity<CvVariant>().Property(x => x.PublicSlug).HasMaxLength(64);
+        modelBuilder.Entity<CvVariantVersion>().Property(x => x.OwnerUserId).HasMaxLength(255);
         modelBuilder.Entity<CvVariant>()
             .HasIndex(x => x.PublicSlug)
             .IsUnique();
@@ -324,6 +330,9 @@ namespace JobTrackerApi.Data
         // docs/architecture/ai-career-assistant.md.
         modelBuilder.Entity<AiInteraction>()
             .HasQueryFilter(x => CurrentUserId != null && x.OwnerUserId == CurrentUserId);
+        // varchar (not longtext) for the indexed columns — see the CvVariant note above.
+        modelBuilder.Entity<AiInteraction>().Property(x => x.OwnerUserId).HasMaxLength(255);
+        modelBuilder.Entity<AiInteraction>().Property(x => x.Module).HasMaxLength(64);
         modelBuilder.Entity<AiInteraction>()
             .HasIndex(x => new { x.OwnerUserId, x.JobApplicationId, x.Module, x.CreatedAtUtc });
         modelBuilder.Entity<AiInteraction>()

JobTrackerApi/Migrations/20260718074509_AddCvVariants.cs

@@ -8,90 +8,20 @@ namespace JobTrackerApi.Migrations
     /// <inheritdoc />
     public partial class AddCvVariants : Migration
     {
+        // Intentionally a no-op. CvVariants/CvVariantVersions are provisioned by the reconciler in
+        // StartupInitializationExtensions (idempotent, MySQL-safe: varchar not longtext so MariaDB can
+        // index PublicSlug/OwnerUserId). The original CreateTable + CREATE INDEX here indexed unbounded
+        // string columns, which succeeds on SQLite but throws on MariaDB ("BLOB/TEXT column used in key
+        // specification without a key length"), crashing backend startup on prod. Reconciler-owned now,
+        // like CareerProfiles/AiWorkspaceNotes. This migration stays recorded so the chain is intact.
         /// <inheritdoc />
         protected override void Up(MigrationBuilder migrationBuilder)
         {
-            migrationBuilder.CreateTable(
-                name: "CvVariants",
-                columns: table => new
-                {
-                    Id = table.Column<int>(type: "INTEGER", nullable: false)
-                        .Annotation("Sqlite:Autoincrement", true),
-                    OwnerUserId = table.Column<string>(type: "TEXT", nullable: false),
-                    PublicSlug = table.Column<string>(type: "TEXT", nullable: false),
-                    Name = table.Column<string>(type: "TEXT", nullable: false),
-                    JobApplicationId = table.Column<int>(type: "INTEGER", nullable: true),
-                    SettingsJson = table.Column<string>(type: "TEXT", nullable: false),
-                    IsPublic = table.Column<bool>(type: "INTEGER", nullable: false),
-                    Version = table.Column<int>(type: "INTEGER", nullable: false),
-                    CreatedAtUtc = table.Column<DateTimeOffset>(type: "TEXT", nullable: false),
-                    UpdatedAtUtc = table.Column<DateTimeOffset>(type: "TEXT", nullable: false)
-                },
-                constraints: table =>
-                {
-                    table.PrimaryKey("PK_CvVariants", x => x.Id);
-                    table.ForeignKey(
-                        name: "FK_CvVariants_JobApplications_JobApplicationId",
-                        column: x => x.JobApplicationId,
-                        principalTable: "JobApplications",
-                        principalColumn: "Id",
-                        onDelete: ReferentialAction.SetNull);
-                });
-
-            migrationBuilder.CreateTable(
-                name: "CvVariantVersions",
-                columns: table => new
-                {
-                    Id = table.Column<int>(type: "INTEGER", nullable: false)
-                        .Annotation("Sqlite:Autoincrement", true),
-                    OwnerUserId = table.Column<string>(type: "TEXT", nullable: false),
-                    CvVariantId = table.Column<int>(type: "INTEGER", nullable: false),
-                    Version = table.Column<int>(type: "INTEGER", nullable: false),
-                    SettingsJson = table.Column<string>(type: "TEXT", nullable: false),
-                    Source = table.Column<string>(type: "TEXT", nullable: false),
-                    CreatedAtUtc = table.Column<DateTimeOffset>(type: "TEXT", nullable: false)
-                },
-                constraints: table =>
-                {
-                    table.PrimaryKey("PK_CvVariantVersions", x => x.Id);
-                    table.ForeignKey(
-                        name: "FK_CvVariantVersions_CvVariants_CvVariantId",
-                        column: x => x.CvVariantId,
-                        principalTable: "CvVariants",
-                        principalColumn: "Id",
-                        onDelete: ReferentialAction.Cascade);
-                });
-
-            migrationBuilder.CreateIndex(
-                name: "IX_CvVariants_JobApplicationId",
-                table: "CvVariants",
-                column: "JobApplicationId");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_CvVariants_OwnerUserId_UpdatedAtUtc",
-                table: "CvVariants",
-                columns: new[] { "OwnerUserId", "UpdatedAtUtc" });
-
-            migrationBuilder.CreateIndex(
-                name: "IX_CvVariants_PublicSlug",
-                table: "CvVariants",
-                column: "PublicSlug",
-                unique: true);
-
-            migrationBuilder.CreateIndex(
-                name: "IX_CvVariantVersions_CvVariantId_Version",
-                table: "CvVariantVersions",
-                columns: new[] { "CvVariantId", "Version" });
         }
 
         /// <inheritdoc />
         protected override void Down(MigrationBuilder migrationBuilder)
         {
-            migrationBuilder.DropTable(
-                name: "CvVariantVersions");
-
-            migrationBuilder.DropTable(
-                name: "CvVariants");
         }
     }
 }

JobTrackerApi/Migrations/20260718131138_AddAiInteractions.cs

@@ -8,51 +8,18 @@ namespace JobTrackerApi.Migrations
     /// <inheritdoc />
     public partial class AddAiInteractions : Migration
     {
+        // Intentionally a no-op — AiInteractions is provisioned by the reconciler in
+        // StartupInitializationExtensions (idempotent, MySQL-safe: Module/OwnerUserId are varchar so
+        // MariaDB can index them). The original CREATE INDEX here indexed unbounded string columns,
+        // which crashes backend startup on MariaDB. See the AddCvVariants migration for the full note.
         /// <inheritdoc />
         protected override void Up(MigrationBuilder migrationBuilder)
         {
-            migrationBuilder.CreateTable(
-                name: "AiInteractions",
-                columns: table => new
-                {
-                    Id = table.Column<int>(type: "INTEGER", nullable: false)
-                        .Annotation("Sqlite:Autoincrement", true),
-                    OwnerUserId = table.Column<string>(type: "TEXT", nullable: false),
-                    JobApplicationId = table.Column<int>(type: "INTEGER", nullable: false),
-                    Module = table.Column<string>(type: "TEXT", nullable: false),
-                    Mode = table.Column<string>(type: "TEXT", nullable: true),
-                    Title = table.Column<string>(type: "TEXT", nullable: false),
-                    Provider = table.Column<string>(type: "TEXT", nullable: false),
-                    ResultJson = table.Column<string>(type: "TEXT", nullable: false),
-                    CreatedAtUtc = table.Column<DateTimeOffset>(type: "TEXT", nullable: false)
-                },
-                constraints: table =>
-                {
-                    table.PrimaryKey("PK_AiInteractions", x => x.Id);
-                    table.ForeignKey(
-                        name: "FK_AiInteractions_JobApplications_JobApplicationId",
-                        column: x => x.JobApplicationId,
-                        principalTable: "JobApplications",
-                        principalColumn: "Id",
-                        onDelete: ReferentialAction.Cascade);
-                });
-
-            migrationBuilder.CreateIndex(
-                name: "IX_AiInteractions_JobApplicationId",
-                table: "AiInteractions",
-                column: "JobApplicationId");
-
-            migrationBuilder.CreateIndex(
-                name: "IX_AiInteractions_OwnerUserId_JobApplicationId_Module_CreatedAtUtc",
-                table: "AiInteractions",
-                columns: new[] { "OwnerUserId", "JobApplicationId", "Module", "CreatedAtUtc" });
         }
 
         /// <inheritdoc />
         protected override void Down(MigrationBuilder migrationBuilder)
         {
-            migrationBuilder.DropTable(
-                name: "AiInteractions");
         }
     }
 }

JobTrackerApi/Services/StartupInitializationExtensions.cs

@@ -104,6 +104,45 @@ public static class StartupInitializationExtensions
         return cmd.ExecuteScalar() is not null;
     }
 
+    // A migration scaffolded against SQLite bakes SQLite type names into its DDL ("TEXT" for
+    // DateTimeOffset, "INTEGER" for bool/int, no AUTO_INCREMENT). Run against MariaDB it produces a
+    // structurally wrong table -- and a composite index over a TEXT column then blows MySQL's
+    // 3072-byte key limit, which is what crashed backend startup on prod. Detect that shape by
+    // probing one column's data type and rebuild the table from the correct MySQL DDL.
+    //
+    // Guarded on row count: an empty malformed table is dropped and recreated; a table with ANY rows
+    // is left untouched (never destroy user data -- surface it instead of silently deleting).
+    private static bool DropMalformedMySqlTable(DbConnection c, string table, string probeColumn, string expectedDataType)
+    {
+        if (!HasMySqlTable(c, table)) return false;
+
+        string? actual;
+        using (var probe = c.CreateCommand())
+        {
+            probe.CommandText = "SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = @schema AND TABLE_NAME = @table AND COLUMN_NAME = @column LIMIT 1;";
+            var s = probe.CreateParameter(); s.ParameterName = "@schema"; s.Value = c.Database; probe.Parameters.Add(s);
+            var t = probe.CreateParameter(); t.ParameterName = "@table"; t.Value = table; probe.Parameters.Add(t);
+            var col = probe.CreateParameter(); col.ParameterName = "@column"; col.Value = probeColumn; probe.Parameters.Add(col);
+            actual = probe.ExecuteScalar() as string;
+        }
+
+        // Unknown column or already the right type: nothing to repair.
+        if (string.IsNullOrEmpty(actual) || string.Equals(actual, expectedDataType, StringComparison.OrdinalIgnoreCase)) return false;
+
+        long rows;
+        using (var count = c.CreateCommand())
+        {
+            count.CommandText = $"SELECT COUNT(*) FROM `{table}`;";
+            rows = Convert.ToInt64(count.ExecuteScalar() ?? 0L);
+        }
+        if (rows > 0) return false;
+
+        using var drop = c.CreateCommand();
+        drop.CommandText = $"DROP TABLE `{table}`;";
+        drop.ExecuteNonQuery();
+        return true;
+    }
+
     private static bool MySqlColumnExists(DbConnection c, string table, string column)
     {
         using var cmd = c.CreateCommand();
@@ -760,6 +799,65 @@ public static class StartupInitializationExtensions
                     Exec(c, """CREATE UNIQUE INDEX IF NOT EXISTS "IX_AiWorkspaceNotes_OwnerUserId_JobApplicationId_NoteType" ON "AiWorkspaceNotes" ("OwnerUserId", "JobApplicationId", "NoteType");""");
                 }
 
+                // Phase 4 CV Builder: a variant is a lens over the master profile; versions are its
+                // autosave history. Reconciler-owned (not migration-owned) so the schema is MySQL-safe
+                // on prod -- see the AddCvVariants migration note. docs/architecture/cv-builder.md.
+                static void EnsureCvBuilderTables(DbConnection c)
+                {
+                    Exec(c, """
+        CREATE TABLE IF NOT EXISTS "CvVariants" (
+            "Id" INTEGER NOT NULL CONSTRAINT "PK_CvVariants" PRIMARY KEY AUTOINCREMENT,
+            "OwnerUserId" TEXT NOT NULL,
+            "PublicSlug" TEXT NOT NULL,
+            "Name" TEXT NOT NULL,
+            "JobApplicationId" INTEGER NULL,
+            "SettingsJson" TEXT NOT NULL,
+            "IsPublic" INTEGER NOT NULL,
+            "Version" INTEGER NOT NULL,
+            "CreatedAtUtc" TEXT NOT NULL,
+            "UpdatedAtUtc" TEXT NOT NULL,
+            CONSTRAINT "FK_CvVariants_JobApplications_JobApplicationId" FOREIGN KEY ("JobApplicationId") REFERENCES "JobApplications" ("Id") ON DELETE SET NULL
+        );
+        """);
+                    Exec(c, """
+        CREATE TABLE IF NOT EXISTS "CvVariantVersions" (
+            "Id" INTEGER NOT NULL CONSTRAINT "PK_CvVariantVersions" PRIMARY KEY AUTOINCREMENT,
+            "OwnerUserId" TEXT NOT NULL,
+            "CvVariantId" INTEGER NOT NULL,
+            "Version" INTEGER NOT NULL,
+            "SettingsJson" TEXT NOT NULL,
+            "Source" TEXT NOT NULL,
+            "CreatedAtUtc" TEXT NOT NULL,
+            CONSTRAINT "FK_CvVariantVersions_CvVariants_CvVariantId" FOREIGN KEY ("CvVariantId") REFERENCES "CvVariants" ("Id") ON DELETE CASCADE
+        );
+        """);
+                    Exec(c, """CREATE INDEX IF NOT EXISTS "IX_CvVariants_JobApplicationId" ON "CvVariants" ("JobApplicationId");""");
+                    Exec(c, """CREATE INDEX IF NOT EXISTS "IX_CvVariants_OwnerUserId_UpdatedAtUtc" ON "CvVariants" ("OwnerUserId", "UpdatedAtUtc");""");
+                    Exec(c, """CREATE UNIQUE INDEX IF NOT EXISTS "IX_CvVariants_PublicSlug" ON "CvVariants" ("PublicSlug");""");
+                    Exec(c, """CREATE INDEX IF NOT EXISTS "IX_CvVariantVersions_CvVariantId_Version" ON "CvVariantVersions" ("CvVariantId", "Version");""");
+                }
+
+                // Phase 5 AI Workspace: append-only AI interaction history per job application.
+                static void EnsureAiInteractionsTable(DbConnection c)
+                {
+                    Exec(c, """
+        CREATE TABLE IF NOT EXISTS "AiInteractions" (
+            "Id" INTEGER NOT NULL CONSTRAINT "PK_AiInteractions" PRIMARY KEY AUTOINCREMENT,
+            "OwnerUserId" TEXT NOT NULL,
+            "JobApplicationId" INTEGER NOT NULL,
+            "Module" TEXT NOT NULL,
+            "Mode" TEXT NULL,
+            "Title" TEXT NOT NULL,
+            "Provider" TEXT NOT NULL,
+            "ResultJson" TEXT NOT NULL,
+            "CreatedAtUtc" TEXT NOT NULL,
+            CONSTRAINT "FK_AiInteractions_JobApplications_JobApplicationId" FOREIGN KEY ("JobApplicationId") REFERENCES "JobApplications" ("Id") ON DELETE CASCADE
+        );
+        """);
+                    Exec(c, """CREATE INDEX IF NOT EXISTS "IX_AiInteractions_JobApplicationId" ON "AiInteractions" ("JobApplicationId");""");
+                    Exec(c, """CREATE INDEX IF NOT EXISTS "IX_AiInteractions_Owner_Job_Module_Created" ON "AiInteractions" ("OwnerUserId", "JobApplicationId", "Module", "CreatedAtUtc");""");
+                }
+
                 EnsureGmailConnectionsTable(conn);
                 EnsureMicrosoftGraphConnectionsTable(conn);
                 EnsureImapConnectionsTable(conn);
@@ -770,6 +868,8 @@ public static class StartupInitializationExtensions
                 EnsureCareerProfileTables(conn);
                 EnsureInterviewPrepNotesTable(conn);
                 EnsureAiWorkspaceNotesTable(conn);
+                EnsureCvBuilderTables(conn);
+                EnsureAiInteractionsTable(conn);
 
                 // Legacy DB signature: migration history exists (AddCorrespondence applied), but 20260310195000 not recorded,
                 // and at least one of the new columns already exists.
@@ -1241,6 +1341,93 @@ public static class StartupInitializationExtensions
                         cmd.ExecuteNonQuery();
                     }
 
+                    // Phase 4 CV Builder + Phase 5 AI Workspace. Reconciler-owned rather than
+                    // migration-owned: those migrations were scaffolded against SQLite, so on MariaDB
+                    // they emit TEXT datetimes and a PK with no AUTO_INCREMENT, and the composite
+                    // index over a TEXT column then exceeds MySQL's 3072-byte key limit -- which
+                    // crashed backend startup on prod. Drop any such half-built table (only when it
+                    // holds no rows) and rebuild from the correct MySQL DDL below.
+                    // Children first: CvVariantVersions FKs into CvVariants.
+                    DropMalformedMySqlTable(conn, "CvVariantVersions", "CreatedAtUtc", "datetime");
+                    DropMalformedMySqlTable(conn, "CvVariants", "UpdatedAtUtc", "datetime");
+                    DropMalformedMySqlTable(conn, "AiInteractions", "CreatedAtUtc", "datetime");
+
+                    if (!HasMySqlTable(conn, "CvVariants"))
+                    {
+                        using var cmd = conn.CreateCommand();
+                        cmd.CommandText = @"CREATE TABLE IF NOT EXISTS `CvVariants` (
+        `Id` int NOT NULL AUTO_INCREMENT,
+        `OwnerUserId` varchar(255) NOT NULL,
+        `PublicSlug` varchar(64) NOT NULL,
+        `Name` varchar(255) NOT NULL,
+        `JobApplicationId` int NULL,
+        `SettingsJson` longtext NOT NULL,
+        `IsPublic` tinyint(1) NOT NULL,
+        `Version` int NOT NULL,
+        `CreatedAtUtc` datetime(6) NOT NULL,
+        `UpdatedAtUtc` datetime(6) NOT NULL,
+        PRIMARY KEY (`Id`),
+        CONSTRAINT `FK_CvVariants_JobApplications_JobApplicationId` FOREIGN KEY (`JobApplicationId`) REFERENCES `JobApplications` (`Id`) ON DELETE SET NULL
+        );";
+                        cmd.ExecuteNonQuery();
+                    }
+
+                    if (!HasMySqlTable(conn, "CvVariantVersions"))
+                    {
+                        using var cmd = conn.CreateCommand();
+                        cmd.CommandText = @"CREATE TABLE IF NOT EXISTS `CvVariantVersions` (
+        `Id` int NOT NULL AUTO_INCREMENT,
+        `OwnerUserId` varchar(255) NOT NULL,
+        `CvVariantId` int NOT NULL,
+        `Version` int NOT NULL,
+        `SettingsJson` longtext NOT NULL,
+        `Source` varchar(100) NOT NULL,
+        `CreatedAtUtc` datetime(6) NOT NULL,
+        PRIMARY KEY (`Id`),
+        CONSTRAINT `FK_CvVariantVersions_CvVariants_CvVariantId` FOREIGN KEY (`CvVariantId`) REFERENCES `CvVariants` (`Id`) ON DELETE CASCADE
+        );";
+                        cmd.ExecuteNonQuery();
+                    }
+
+                    if (!HasMySqlTable(conn, "AiInteractions"))
+                    {
+                        using var cmd = conn.CreateCommand();
+                        cmd.CommandText = @"CREATE TABLE IF NOT EXISTS `AiInteractions` (
+        `Id` int NOT NULL AUTO_INCREMENT,
+        `OwnerUserId` varchar(255) NOT NULL,
+        `JobApplicationId` int NOT NULL,
+        `Module` varchar(64) NOT NULL,
+        `Mode` varchar(64) NULL,
+        `Title` varchar(255) NOT NULL,
+        `Provider` varchar(100) NOT NULL,
+        `ResultJson` longtext NOT NULL,
+        `CreatedAtUtc` datetime(6) NOT NULL,
+        PRIMARY KEY (`Id`),
+        CONSTRAINT `FK_AiInteractions_JobApplications_JobApplicationId` FOREIGN KEY (`JobApplicationId`) REFERENCES `JobApplications` (`Id`) ON DELETE CASCADE
+        );";
+                        cmd.ExecuteNonQuery();
+                    }
+
+                    EnsureMySqlAutoIncrementPrimaryKey(conn, "CvVariants", "Id");
+                    EnsureMySqlAutoIncrementPrimaryKey(conn, "CvVariantVersions", "Id");
+                    EnsureMySqlAutoIncrementPrimaryKey(conn, "AiInteractions", "Id");
+
+                    foreach (var (ixTable, ixName, ixColumns, ixUnique) in new[]
+                    {
+                        ("CvVariants", "IX_CvVariants_JobApplicationId", "`JobApplicationId`", false),
+                        ("CvVariants", "IX_CvVariants_OwnerUserId_UpdatedAtUtc", "`OwnerUserId`, `UpdatedAtUtc`", false),
+                        ("CvVariants", "IX_CvVariants_PublicSlug", "`PublicSlug`", true),
+                        ("CvVariantVersions", "IX_CvVariantVersions_CvVariantId_Version", "`CvVariantId`, `Version`", false),
+                        ("AiInteractions", "IX_AiInteractions_JobApplicationId", "`JobApplicationId`", false),
+                        ("AiInteractions", "IX_AiInteractions_Owner_Job_Module_Created", "`OwnerUserId`, `JobApplicationId`, `Module`, `CreatedAtUtc`", false),
+                    })
+                    {
+                        if (MySqlIndexExists(conn, ixTable, ixName)) continue;
+                        using var cmd = conn.CreateCommand();
+                        cmd.CommandText = $"CREATE {(ixUnique ? "UNIQUE " : string.Empty)}INDEX `{ixName}` ON `{ixTable}` ({ixColumns});";
+                        cmd.ExecuteNonQuery();
+                    }
+
                     if (!MySqlIndexExists(conn, "CareerProfiles", "IX_CareerProfiles_OwnerUserId"))
                     {
                         using var cmd = conn.CreateCommand();