add translation support for portions, baking, cook times, and ingredient units

Add comprehensive translation support for previously untranslatable fields:
- Portions (serving sizes)
- Time fields (preparation, cooking, total_time)
- Baking properties (temperature, length, mode)
- Fermentation times (bulk, final)
- Ingredient units (EL→tbsp, TL→tsp, etc.)

Fix terminology replacement to work correctly:
- Pre-process German cooking terms BEFORE sending to DeepL
- Post-process to convert US English to British English AFTER DeepL
- Split applyIngredientTerminology into replaceGermanCookingTerms (pre) and applyBritishEnglish (post)

Database schema:
- Add translatable fields to translations.en object

Translation service:
- Include new fields and ingredient units in batch translation
- Add field-specific translation in translateFields()
- Update change detection to track new fields
- Pre-process all texts to replace German terms before DeepL
- Post-process all texts to apply British English after DeepL

UI components:
- Display all new fields in translation approval interface
- Add editable inputs for English translations
- Support nested field editing (baking.temperature, fermentation.bulk, etc.)

Fix changed fields detection:
- Only show changed fields when editing existing translations
- Don't show false warnings for first-time translations

src/routes/[recipeLang=recipeLang]/edit/[name]/+page.svelte

@@ -127,7 +127,9 @@
 
 		const fieldsToCheck = [
 			'name', 'description', 'preamble', 'addendum',
-			'note', 'category', 'tags', 'ingredients', 'instructions'
+			'note', 'category', 'tags', 'portions', 'preparation',
+			'cooking', 'total_time', 'baking', 'fermentation',
+			'ingredients', 'instructions'
 		];
 
 		for (const field of fieldsToCheck) {
@@ -143,7 +145,9 @@
 
 	// Show translation workflow before submission
 	function prepareSubmit() {
-		changedFields = detectChangedFields();
+		// Only detect changed fields if there's an existing translation
+		// For first-time translations, changedFields should be empty
+		changedFields = translationData ? detectChangedFields() : [];
 		showTranslationWorkflow = true;
 
 		// Scroll to translation section