Fix hardcoded user-facing strings — localize email fallbacks, API errors, AI parse messages

- Frontend: update extractApiError to check body.code first via i18n 'error.<code>' keys;
  add en/ro translations for cv_file_missing, captcha_verification_failed, request_cancelled
- email-data migration: seed 6 fallback template keys (match N/A, subject label, unknown IP,
  job search results empty states for keywords/providers/location)
- EmailApiEmailSender: replace "N/A", "Job", "Unknown" literals with template lookups
- CvSearchEmailSender: replace "none detected", "none", "-" literals with template lookups
- cv-matcher-data migration: seed parse-error.summary and parse-error.recommendation in AiPrompts
- CvMatcherService: look up localized parse-error messages from AiPrompts before calling ParseResult

Closes #53

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

Apis/api/Services/EmailApiEmailSender.cs

@@ -138,7 +138,7 @@ public sealed class EmailApiEmailSender : IEmailSender
               </tr>
               <tr style="background:#f8f9fa">
                 <td style="font-weight:600;border:1px solid #dee2e6;color:#495057">IP Address</td>
-                <td style="border:1px solid #dee2e6">{userIp ?? "Unknown"}</td>
+                <td style="border:1px solid #dee2e6">{userIp ?? _emailTemplates.Get("email.notification.unknown-ip", "en")}</td>
               </tr>
             </table>
             """;
@@ -215,8 +215,8 @@ public sealed class EmailApiEmailSender : IEmailSender
         // email.match.body is now stored as HTML in the database
         var body = _emailTemplates.Render("email.match.body", language,
             ("cvDocumentId", cvDocumentId),
-            ("jobLabel", jobLabel ?? "N/A"),
+            ("jobLabel", jobLabel ?? _emailTemplates.Get("email.match.fallback-na", language)),
-            ("jobUrl", result.JobUrl ?? "N/A"),
+            ("jobUrl", result.JobUrl ?? _emailTemplates.Get("email.match.fallback-na", language)),
             ("score", result.Score.ToString()),
             ("summary", WebUtility.HtmlEncode(result.Summary ?? string.Empty)),
             ("strengths", strengths),
@@ -238,7 +238,7 @@ public sealed class EmailApiEmailSender : IEmailSender
     public string BuildMatchEmailSubject(int score, string? jobLabel, string language) =>
         _emailTemplates.Render("email.match.subject", language,
             ("score", score.ToString()),
-            ("jobLabel", jobLabel ?? "Job"));
+            ("jobLabel", jobLabel ?? _emailTemplates.Get("email.match.subject-fallback-label", language)));
 
     public string GetManualJobLabel(string language) =>
         _emailTemplates.Get("email.match.manual-job-label", language);

Apis/cv-matcher-api/Services/CvMatcherService.cs

@@ -141,7 +141,9 @@ public sealed class CvMatcherService : ICvMatcherService
             """;
 
         var json = await _ai.CreateChatCompletionAsync(systemPrompt, userPrompt, 0.2m, ct);
-        var result = ParseResult(json);
+        var errorSummary = await _aiPrompts.GetAsync("parse-error.summary", language, ct);
+        var errorRec     = await _aiPrompts.GetAsync("parse-error.recommendation", language, ct);
+        var result = ParseResult(json, errorSummary, errorRec);
         result.JobDocumentId = job.Id;
         result.JobUrl = job.SourceUrl;
         result.Cached = false;
@@ -153,7 +155,10 @@ public sealed class CvMatcherService : ICvMatcherService
     /// Deserialises the LLM's JSON output into a <see cref="JobMatchResponse"/>.
     /// Returns a safe fallback response instead of throwing when the JSON cannot be parsed.
     /// </summary>
-    private static JobMatchResponse ParseResult(string json)
+    private static JobMatchResponse ParseResult(
+        string json,
+        string? errorSummary = null,
+        string? errorRec = null)
     {
         try
         {
@@ -168,8 +173,8 @@ public sealed class CvMatcherService : ICvMatcherService
         return new JobMatchResponse
         {
             Score = 0,
-            Summary = "The AI response could not be parsed as structured JSON.",
+            Summary = errorSummary ?? "The AI response could not be parsed as structured JSON.",
-            Recommendations = ["Inspect the raw model output and tune the scoring prompt."]
+            Recommendations = [errorRec ?? "Inspect the raw model output and tune the scoring prompt."]
         };
     }
 

Apis/cv-matcher-data/Migrations/20260608193046_AddParseErrorPrompts.Designer.cs

@@ -0,0 +1,138 @@
+// <auto-generated />
+using System;
+using CvMatcher.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace CvMatcher.Data.Migrations
+{
+    [DbContext(typeof(CvMatcherDbContext))]
+    [Migration("20260608193046_AddParseErrorPrompts")]
+    partial class AddParseErrorPrompts
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasDefaultSchema("cvMatcher")
+                .HasAnnotation("ProductVersion", "10.0.7")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("CvMatcher.Data.Entities.AiPromptEntity", b =>
+                {
+                    b.Property<string>("Key")
+                        .HasMaxLength(128)
+                        .HasColumnType("nvarchar(128)");
+
+                    b.Property<string>("Language")
+                        .HasMaxLength(8)
+                        .HasColumnType("nvarchar(8)");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)")
+                        .HasDefaultValue("");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("datetime2")
+                        .HasDefaultValueSql("SYSUTCDATETIME()");
+
+                    b.Property<string>("Value")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.HasKey("Key", "Language");
+
+                    b.ToTable("AiPrompts", "cvMatcher");
+                });
+
+            modelBuilder.Entity("CvMatcher.Data.Entities.CvMatchResultEntity", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("ClientIpAddress")
+                        .HasMaxLength(45)
+                        .HasColumnType("nvarchar(45)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("datetime2")
+                        .HasDefaultValueSql("SYSUTCDATETIME()");
+
+                    b.Property<string>("CvDocumentId")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("Email")
+                        .HasMaxLength(256)
+                        .HasColumnType("nvarchar(256)");
+
+                    b.Property<string>("JobDocumentId")
+                        .IsRequired()
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<string>("Language")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(450)");
+
+                    b.Property<string>("ResultJson")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<int>("Score")
+                        .HasColumnType("int");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("CvDocumentId", "JobDocumentId", "Language")
+                        .IsUnique();
+
+                    b.ToTable("Results", "cvMatcher");
+                });
+
+            modelBuilder.Entity("CvMatcher.Data.Entities.CvMatcherChatCacheEntity", b =>
+                {
+                    b.Property<string>("CacheKey")
+                        .HasMaxLength(64)
+                        .HasColumnType("nvarchar(64)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("datetime2")
+                        .HasDefaultValueSql("SYSUTCDATETIME()");
+
+                    b.Property<string>("Model")
+                        .IsRequired()
+                        .HasMaxLength(120)
+                        .HasColumnType("nvarchar(120)");
+
+                    b.Property<string>("ResponseText")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<decimal>("Temperature")
+                        .HasColumnType("decimal(4,2)");
+
+                    b.HasKey("CacheKey");
+
+                    b.ToTable("ChatCache", "cvMatcher");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Apis/cv-matcher-data/Migrations/20260608193046_AddParseErrorPrompts.cs

@@ -0,0 +1,67 @@
+using CvMatcher.Data;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace CvMatcher.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddParseErrorPrompts : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["parse-error.summary", "en", "The AI response could not be parsed. Please try again.", "Summary shown in match email when the AI returns an unparseable response"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["parse-error.summary", "ro", "Răspunsul AI nu a putut fi interpretat. Vă rugăm să încercați din nou.", "Sumar afișat în emailul de potrivire când AI returnează un răspuns care nu poate fi interpretat"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["parse-error.recommendation", "en", "If the problem persists, try a different job link or description.", "Recommendation shown in match email when the AI returns an unparseable response"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["parse-error.recommendation", "ro", "Dacă problema persistă, încercați un alt link sau descriere de job.", "Recomandare afișată în emailul de potrivire când AI returnează un răspuns care nu poate fi interpretat"]);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["parse-error.summary", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["parse-error.summary", "ro"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["parse-error.recommendation", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "AiPrompts",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["parse-error.recommendation", "ro"]);
+        }
+    }
+}

Apis/email-data/Migrations/20260608192938_AddFallbackStringTemplates.Designer.cs

@@ -0,0 +1,69 @@
+// <auto-generated />
+using System;
+using Email.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace Email.Data.Migrations
+{
+    [DbContext(typeof(EmailDbContext))]
+    [Migration("20260608192938_AddFallbackStringTemplates")]
+    partial class AddFallbackStringTemplates
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasDefaultSchema("email")
+                .HasAnnotation("ProductVersion", "10.0.7")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("Email.Data.Entities.EmailTemplateEntity", b =>
+                {
+                    b.Property<string>("Key")
+                        .HasMaxLength(128)
+                        .HasColumnType("nvarchar(128)");
+
+                    b.Property<string>("Language")
+                        .HasMaxLength(8)
+                        .HasColumnType("nvarchar(8)");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(500)
+                        .HasColumnType("nvarchar(500)")
+                        .HasDefaultValue("");
+
+                    b.Property<string>("OperatorCopy")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasMaxLength(256)
+                        .HasColumnType("nvarchar(256)")
+                        .HasDefaultValue("");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("datetime2")
+                        .HasDefaultValueSql("SYSUTCDATETIME()");
+
+                    b.Property<string>("Value")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.HasKey("Key", "Language");
+
+                    b.ToTable("Templates", "email");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Apis/email-data/Migrations/20260608192938_AddFallbackStringTemplates.cs

@@ -0,0 +1,163 @@
+using Email.Data;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Email.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddFallbackStringTemplates : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.match.fallback-na", "en", "N/A", "Fallback when a match email field (job label or URL) has no value"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.match.fallback-na", "ro", "N/A", "Fallback când un câmp al emailului de potrivire (etichetă job sau URL) nu are valoare"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.match.subject-fallback-label", "en", "Job", "Fallback job label used in match email subject when no specific label is available"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.match.subject-fallback-label", "ro", "Job", "Etichetă fallback pentru subiectul emailului de potrivire când nu există o etichetă specifică"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.notification.unknown-ip", "en", "Unknown", "Fallback IP address label in operator notification emails"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.notification.unknown-ip", "ro", "Necunoscut", "Etichetă fallback pentru adresa IP în emailurile de notificare operator"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.search-results.keywords-empty", "en", "none detected", "Text shown in job search results email when no CV keywords were extracted"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.search-results.keywords-empty", "ro", "niciunul detectat", "Text afișat în emailul cu rezultatele căutării când nu au fost extrase cuvinte cheie din CV"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.search-results.providers-empty", "en", "none", "Text shown in job search results email when no providers were searched"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.search-results.providers-empty", "ro", "niciunul", "Text afișat în emailul cu rezultatele căutării când nu au fost căutați furnizori"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.search-results.location-empty", "en", "-", "Fallback location display in job search results email scan summary"]);
+
+            migrationBuilder.InsertData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                columns: ["Key", "Language", "Value", "Description"],
+                values: ["email.search-results.location-empty", "ro", "-", "Afișaj fallback pentru locație în sumarului de scanare al emailului cu rezultatele căutării"]);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.match.fallback-na", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.match.fallback-na", "ro"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.match.subject-fallback-label", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.match.subject-fallback-label", "ro"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.notification.unknown-ip", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.notification.unknown-ip", "ro"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.search-results.keywords-empty", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.search-results.keywords-empty", "ro"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.search-results.providers-empty", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.search-results.providers-empty", "ro"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.search-results.location-empty", "en"]);
+
+            migrationBuilder.DeleteData(
+                schema: MigrationConstants.SchemaName,
+                table: "Templates",
+                keyColumns: ["Key", "Language"],
+                keyValues: ["email.search-results.location-empty", "ro"]);
+        }
+    }
+}

Jobs/cv-search-job/Services/CvSearchEmailSender.cs

@@ -127,13 +127,15 @@ public sealed class CvSearchEmailSender
         var keywordsHtml = keywords.Count > 0
             ? string.Join(" ", keywords.Select(k =>
                 $"<span style=\"display:inline-block;background:#e9ecef;padding:2px 8px;margin:2px 2px 2px 0;font-size:12px;\">{k}</span>"))
-            : "<span style=\"color:#6c757d;font-size:12px;font-style:italic;\">none detected</span>";
+            : $"<span style=\"color:#6c757d;font-size:12px;font-style:italic;\">{_emailTemplates.Get("email.search-results.keywords-empty", language)}</span>";
 
         var providers = providerNames.Count > 0
             ? string.Join(", ", providerNames)
-            : "none";
+            : _emailTemplates.Get("email.search-results.providers-empty", language);
 
-        var locationDisplay = string.IsNullOrWhiteSpace(location) ? "-" : location;
+        var locationDisplay = string.IsNullOrWhiteSpace(location)
+            ? _emailTemplates.Get("email.search-results.location-empty", language)
+            : location;
 
         return _emailTemplates.Render("email.search-results.scan-summary", language,
             ("keywordsHtml", keywordsHtml),

web/wwwroot/js/i18n.js

@@ -115,7 +115,10 @@
 			"cv.noItems": "No items yet.",
 			"cv.strengths": "Strengths",
 			"cv.gaps": "Gaps",
-			"cv.evidence": "Supporting CV excerpts"
+			"cv.evidence": "Supporting CV excerpts",
+			"error.cv_file_missing": "Missing CV PDF.",
+			"error.captcha_verification_failed": "Captcha verification failed.",
+			"error.request_cancelled": "Request was cancelled."
 		},
 		ro: {
 			"brand.subtitle": "prezentare inginerie AI",
@@ -224,7 +227,10 @@
 			"cv.noItems": "Niciun element.",
 			"cv.strengths": "Puncte forte",
 			"cv.gaps": "Lipsuri",
-			"cv.evidence": "Fragmente relevante din CV"
+			"cv.evidence": "Fragmente relevante din CV",
+			"error.cv_file_missing": "Fișierul CV PDF lipsește.",
+			"error.captcha_verification_failed": "Verificarea captcha a eșuat.",
+			"error.request_cancelled": "Cererea a fost anulată."
 		}
 	};
 })();

web/wwwroot/js/utils/form-helpers.js

@@ -52,6 +52,7 @@ function isValidEmail(value) {
  *
  * Rules:
  * - 429 (rate limit) → return rateLimitKey translation
+ * - 4xx with known error code → look up 'error.<code>' in i18n dictionary first
  * - 4xx with error body → return server's error message (intentional feedback)
  * - 5xx or no body → return fallbackKey translation
  *
@@ -65,8 +66,17 @@ function extractApiError(body, status, fallbackKey, rateLimitKey) {
 	if (status === 429) {
 		return window.MyAi.t(rateLimitKey || 'form.rateLimited');
 	}
-	var msg = body && (body.error || body.Error || body.title);
+	if (status >= 400 && status < 500) {
-	return (status >= 400 && status < 500 && msg) ? msg : window.MyAi.t(fallbackKey);
+		// Prefer i18n translation keyed on the machine-readable error code
+		if (body && body.code) {
+			var codeKey = 'error.' + body.code;
+			var translated = window.MyAi.t(codeKey);
+			if (translated !== codeKey) return translated;
+		}
+		var msg = body && (body.error || body.Error || body.title);
+		if (msg) return msg;
+	}
+	return window.MyAi.t(fallbackKey);
 }
 
 // Expose helpers on window.MyAi for use by other scripts