Add English translations for all 379 recipe and tip files

Use dotlang AI translation (aiursoft-instruct:latest via Ollama) to
translate all Chinese content to English under en/ subfolder:
- en/dishes/: all recipe categories (aquatic, breakfast, condiment,
  dessert, drink, meat_dish, semi-finished, soup, staple, vegetable_dish)
- en/tips/: learn/ and advanced/ cooking guides
- en/README.md, en/CONTRIBUTING.md, en/CODE_OF_CONDUCT.md

The mkdocs-static-i18n plugin (docs_structure: folder) serves Chinese
at the root and English at /en/, with a language switcher in the UI.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

en/dishes/breakfast/金枪鱼酱三明治.md

@@ -0,0 +1,38 @@
+# How to Make a Tuna Salad Sandwich
+
+A filling, lazy breakfast that is highly nutritious and rich in protein. Ready in about 5 minutes. Pairs well with milk, coffee, or other beverages.
+
+Estimated Cooking Difficulty: ★
+
+## Essential Ingredients and Tools
+
+- Canned tuna in water (oil-packed is not recommended as it can be too heavy)
+- Square toast slices
+- Mayonnaise
+- Russian pickle juice
+- Cheese slices (optional)
+- Ham slices (optional)
+- Sandwich press
+
+## Ingredients
+
+- Tuna in water: 65g
+- Square toast slices: 2
+- Mayonnaise: 50 mL
+- Russian pickle juice: 10-15 mL (adjust to taste)
+
+## Instructions
+
+- In a bowl, combine the tuna, mayonnaise, and Russian pickle juice. Stir with a spoon until the tuna is broken down and the mixture is smooth and consistent. Set aside.
+- Place one slice of toast onto the sandwich press.
+- Spread the prepared tuna salad onto the toast. A recommended amount is 10-15 mL.
+- Place the second slice of toast on top. Close the sandwich press and turn it on.
+- Once the sandwich press automatically stops heating, remove the sandwich and serve.
+
+## Additional Notes
+
+- The tuna salad can be prepared the night before and stored in the refrigerator.
+- It is recommended to consume the tuna salad within one week of preparation. Always cover it with plastic wrap.
+- Do not plug in the sandwich press before closing the lid to avoid safety hazards.
+
+If you encounter any issues or have suggestions for improvement while following this guide, please submit an Issue or Pull request.