Remove auto-resize functionality and simplify input field layout

- Remove autoResize() function and calls
- Set input field height to 100% instead of dynamic resizing
- Adjust input padding from var(--size-2-1) to var(--size-2-2)
- Remove explicit height: 100% from edit-mode and submit buttons

Components/ChatWindow.svelte

@@ -107,7 +107,6 @@
 
     textareaElement.textContent = "";
     userRequest = "";
-    autoResize();
 
     await chatService.submit(conversation, editModeActive, currentRequest, {
       onSubmit: () => {
@@ -146,16 +145,6 @@
       if (userRequest.trim() === "") {
         textareaElement.textContent = "";
       }
-      autoResize();
-    }
-  }
-
-  function autoResize() {
-    if (textareaElement) {
-      // For contenteditable divs, reset height and set to scrollHeight
-      textareaElement.style.height = "auto";
-      const newHeight = Math.min(textareaElement.scrollHeight, window.innerHeight * 0.3);
-      textareaElement.style.height = `${newHeight}px`;
     }
   }
 
@@ -276,13 +265,14 @@
   #input-field {
     grid-row: 2;
     grid-column: 2;
+    height: 100%;
     max-height: 30vh;
     border-radius: var(--input-radius);
     font-weight: var(--input-font-weight);
     border-width: var(--input-border-width);
     border-style: solid;
     border-color: var(--background-modifier-border);
-    padding: var(--size-2-1) var(--size-2-3);
+    padding: var(--size-2-2) var(--size-2-3);
     background-color: var(--background-primary);
     font-family: var(--font-interface-theme);
     resize: none;
@@ -332,7 +322,6 @@
   #edit-mode-button {
     grid-row: 2;
     grid-column: 4;
-    height: 100%;
     border-radius: var(--button-radius);
     align-self: end;
     transition-duration: 0.5s;
@@ -341,7 +330,6 @@
   #submit-button {
     grid-row: 2;
     grid-column: 6;
-    height: 100%;
     border-radius: var(--button-radius);
     padding-left: var(--size-4-5);
     padding-right: var(--size-4-5);