fix(i18n): remove duplicate locale keys and guard with a regression test (#2789)

* fix(i18n): remove duplicate locale keys that shadow translations

YAML resolves duplicate keys by silently letting the last occurrence
win, so every duplicated key hides an earlier definition without any
warning:

- transactions/{en,de,nl,hu}.yml defined `transactions.merge_duplicate`
  twice: once as a stale flat string ("Yes, merge them") and once as the
  `success`/`failure` mapping the controllers actually read. The flat
  string is dead either way (the show view reads
  `transactions.show.merge_duplicate`), so drop it.
- securities/fr.yml listed five providers (tiingo, eodhd, alpha_vantage,
  mfapi, binance_public) twice inside `securities.providers`.
- settings/api_keys/hu.yml defined
  `settings.api_keys.created.usage_instructions_title` twice.
- imports/en.yml defined `imports.create.ndjson_uploaded` twice.

All removals keep the currently-winning value, so rendered output is
unchanged; this only makes the files match what I18n already loads.

Add a non-skipped I18nTest case that walks the raw Psych AST of every
file under config/locales and fails on same-level duplicate keys, so
shadowed translations can't sneak back in.

Fixes #1506
Fixes #1502

* Fix linter / merge errors

* fix(i18n): repair duplicate locale regression test

---------

Signed-off-by: Juan José Mata <juanjo.mata@gmail.com>
Co-authored-by: rsnetworkinginc <rsnetworkinginc@users.noreply.github.com>
Co-authored-by: Juan José Mata <juanjo.mata@gmail.com>
Co-authored-by: Juan José Mata <jjmata@jjmata.com>
Co-authored-by: sure-admin <sure-admin@splashblot.com>

config/locales/views/imports/en.yml

@@ -447,7 +447,6 @@ en:
       document_uploaded: Document uploaded successfully.
       document_upload_failed: We couldn't upload the document to the vector store. Please try again.
       invalid_ndjson_file_type: Invalid file type or format. Please upload a valid .ndjson or .json export file.
-      ndjson_uploaded: NDJSON file uploaded successfully.
       document_provider_not_configured: No vector store is configured for document uploads.
     show:
       finalize_upload: Please finalize your file upload.

config/locales/views/securities/fr.yml

@@ -12,9 +12,4 @@ fr:
       tiingo: Tiingo
       twelve_data: Twelve Data
       yahoo_finance: Yahoo Finance
-      tiingo: Tiingo
-      eodhd: EODHD
-      alpha_vantage: Alpha Vantage
-      mfapi: MFAPI.in
-      binance_public: Binance
       moex_public: MOEX

config/locales/views/settings/api_keys/hu.yml

@@ -103,7 +103,6 @@ hu:
         created_label: "Létrehozva:"
         security_note_title: "Fontos biztonsági megjegyzés"
         security_note_body: "Ez az egyetlen alkalom, amikor az API-kulcsod megjelenik. Mindenképpen másold le most és tárold biztonságosan. Ha elveszíted, újat kell generálnod."
-        usage_instructions_title: "Az API-kulcs használata"
         key_name: "Név"
         permissions: "Jogosultságok"
         critical_warning_title: "⚠️ Kritikus: Mentsd el az API-kulcsodat most"

config/locales/views/transactions/de.yml

@@ -97,7 +97,6 @@ de:
     mark_recurring_title: Wiederkehrende Transaktion
     potential_duplicate_title: Mögliches Duplikat erkannt
     potential_duplicate_description: Diese ausstehende Transaktion könnte mit der unten stehenden gebuchten Transaktion übereinstimmen. Wenn ja, führe sie zusammen, um Doppelzählung zu vermeiden.
-    merge_duplicate: Ja, zusammenführen
     keep_both: Nein, beide behalten
     transaction:
       pending: Ausstehend

config/locales/views/transactions/en.yml

@@ -127,7 +127,6 @@ en:
     mark_recurring_title: Recurring Transaction
     potential_duplicate_title: Possible duplicate detected
     potential_duplicate_description: This pending transaction may be the same as the posted transaction below. If so, merge them to avoid double-counting.
-    merge_duplicate: Yes, merge them
     keep_both: No, keep both
     split_parent_row:
       split_label: "Split"

config/locales/views/transactions/hu.yml

@@ -123,7 +123,6 @@ hu:
     mark_recurring_title: Ismétlődő tranzakció
     potential_duplicate_title: Lehetséges duplikátum észlelve
     potential_duplicate_description: Ez a függőben lévő tranzakció megegyezhet az alábbi közzétett tranzakcióval. Ha igen, egyesítsd őket a kettős könyvelés elkerülése érdekében.
-    merge_duplicate: Igen, egyesítsd őket
     keep_both: Nem, mindkettőt tartsd meg
     split_parent_row:
       split_label: "Felosztva"

config/locales/views/transactions/nl.yml

@@ -71,7 +71,6 @@ nl:
     mark_recurring_title: Terugkerende Transactie
     potential_duplicate_title: Mogelijk duplicaat gedetecteerd
     potential_duplicate_description: Deze wachtende transactie kan hetzelfde zijn als de geposte transactie hieronder. Indien ja, voeg ze samen om dubbeltelling te voorkomen.
-    merge_duplicate: Ja, voeg ze samen
     keep_both: Nee, bewaar beide
     transaction:
       pending: Wachtend

config/locales/views/transactions/uk.yml

@@ -122,7 +122,6 @@ uk:
     mark_recurring_title: Повторювана транзакція
     potential_duplicate_title: Виявлено можливий дублікат
     potential_duplicate_description: Ця очікувана транзакція може бути такою ж, як і опублікована транзакція нижче. Якщо так, об'єднайте їх, щоб уникнути подвійного підрахунку.
-    merge_duplicate: Так, об'єднати їх
     keep_both: Ні, залишити обидві
     split_parent_row:
       split_label: "Розділити"

test/i18n_test.rb

@@ -57,6 +57,26 @@ class I18nTest < ActiveSupport::TestCase
     assert_empty inconsistent_interpolations, error_message
   end
 
+  # YAML silently resolves duplicate keys by letting the last occurrence win,
+  # so a duplicated key shadows the earlier definition without any warning
+  # (see #1506 / #1502, where a stale `transactions.merge_duplicate` string
+  # shadowed — or was shadowed by — the `merge_duplicate.success/failure`
+  # mapping in several locales). Parse the raw YAML AST so duplicates can't
+  # sneak back in.
+  def test_no_duplicate_keys_within_locale_files
+    offenses = []
+
+    Dir[File.expand_path("../config/locales/**/*.yml", __dir__)].sort.each do |file|
+      Psych.parse_stream(File.read(file), filename: file).children.each do |doc|
+        offenses.concat(duplicate_key_offenses(doc.root, [], file))
+      end
+    end
+
+    assert_empty offenses,
+                 "Duplicate keys found in locale files (the last occurrence silently wins):\n" \
+                 "#{offenses.map { |offense| "  #{offense}" }.join("\n")}"
+  end
+
   private
     def german_locale_paths
       @german_locale_paths ||= locale_paths.select { |path| path.basename.to_s.match?(/(^|[._-])de\.yml\z/) }
@@ -65,4 +85,33 @@ class I18nTest < ActiveSupport::TestCase
     def locale_paths
       @locale_paths ||= GERMAN_COVERAGE_GLOBS.flat_map { |glob| Pathname.pwd.glob(glob) }.uniq
     end
+
+    def duplicate_key_offenses(node, path, file)
+      offenses = []
+
+      case node
+      when Psych::Nodes::Mapping
+        first_definition_lines = {}
+
+        node.children.each_slice(2) do |key_node, value_node|
+          if key_node.is_a?(Psych::Nodes::Scalar)
+            key_path = path + [ key_node.value ]
+
+            if (first_line = first_definition_lines[key_node.value])
+              offenses << "#{file}:#{key_node.start_line + 1} duplicate key `#{key_path.join(".")}` (first defined on line #{first_line})"
+            else
+              first_definition_lines[key_node.value] = key_node.start_line + 1
+            end
+
+            offenses.concat(duplicate_key_offenses(value_node, key_path, file))
+          else
+            offenses.concat(duplicate_key_offenses(value_node, path, file))
+          end
+        end
+      when Psych::Nodes::Sequence
+        node.children.each { |child| offenses.concat(duplicate_key_offenses(child, path, file)) }
+      end
+
+      offenses
+    end
 end