feat: add media upload API endpoints and repository method for video/audio

- Create MediaModels.kt with MediaUploadResponse and UploadedMedia data classes
- Add uploadMedia() and uploadMediaThumbnail() to GhostApiService
- Add uploadMediaFile(uri) to PostRepository with MIME detection

app/src/main/java/com/swoosh/microblog/data/api/GhostApiService.kt

@@ -1,6 +1,7 @@
 package com.swoosh.microblog.data.api
 
 import com.swoosh.microblog.data.model.GhostSite
+import com.swoosh.microblog.data.model.MediaUploadResponse
 import com.swoosh.microblog.data.model.MembersResponse
 import com.swoosh.microblog.data.model.PageWrapper
 import com.swoosh.microblog.data.model.PagesResponse
@@ -114,6 +115,20 @@ interface GhostApiService {
         @Part file: MultipartBody.Part,
         @Part("purpose") purpose: RequestBody
     ): Response<ImageUploadResponse>
+
+    @Multipart
+    @POST("ghost/api/admin/media/upload/")
+    suspend fun uploadMedia(
+        @Part file: MultipartBody.Part,
+        @Part("ref") ref: RequestBody? = null
+    ): Response<MediaUploadResponse>
+
+    @Multipart
+    @POST("ghost/api/admin/media/thumbnail/upload/")
+    suspend fun uploadMediaThumbnail(
+        @Part file: MultipartBody.Part,
+        @Part("ref") ref: RequestBody? = null
+    ): Response<MediaUploadResponse>
 }
 
 data class ImageUploadResponse(

app/src/main/java/com/swoosh/microblog/data/model/MediaModels.kt

@@ -0,0 +1,11 @@
+package com.swoosh.microblog.data.model
+
+data class MediaUploadResponse(
+    val media: List<UploadedMedia>
+)
+
+data class UploadedMedia(
+    val url: String,
+    val ref: String?,
+    val fileName: String?
+)

app/src/main/java/com/swoosh/microblog/data/repository/PostRepository.kt

@@ -113,8 +113,8 @@ class PostRepository(private val context: Context) {
     suspend fun uploadImage(uri: Uri): Result<String> =
         withContext(Dispatchers.IO) {
             try {
-                val file = copyUriToTempFile(uri)
                 val mimeType = context.contentResolver.getType(uri) ?: "image/jpeg"
+                val file = copyUriToTempFile(uri, ".jpg")
                 val requestBody = file.asRequestBody(mimeType.toMediaType())
                 val part = MultipartBody.Part.createFormData("file", file.name, requestBody)
                 val purpose = "image".toRequestBody("text/plain".toMediaType())
@@ -156,10 +156,41 @@ class PostRepository(private val context: Context) {
             }
         }
 
-    private fun copyUriToTempFile(uri: Uri): File {
+    /**
+     * Uploads a media file (video or audio) to the Ghost media upload endpoint.
+     * Determines MIME type from the content resolver. Returns the uploaded URL on success.
+     */
+    suspend fun uploadMediaFile(uri: Uri): Result<String> =
+        withContext(Dispatchers.IO) {
+            try {
+                val mimeType = context.contentResolver.getType(uri) ?: "application/octet-stream"
+                val extension = when {
+                    mimeType.startsWith("video/") -> mimeType.substringAfter("video/").let { ".$it" }
+                    mimeType.startsWith("audio/") -> mimeType.substringAfter("audio/").let { ".$it" }
+                    else -> ""
+                }
+                val file = copyUriToTempFile(uri, extension)
+                val requestBody = file.asRequestBody(mimeType.toMediaType())
+                val part = MultipartBody.Part.createFormData("file", file.name, requestBody)
+
+                val response = getApi().uploadMedia(part)
+                file.delete()
+
+                if (response.isSuccessful) {
+                    val url = response.body()!!.media.first().url
+                    Result.success(url)
+                } else {
+                    Result.failure(Exception("Media upload failed ${response.code()}"))
+                }
+            } catch (e: Exception) {
+                Result.failure(e)
+            }
+        }
+
+    private fun copyUriToTempFile(uri: Uri, extension: String = ".jpg"): File {
         val inputStream = context.contentResolver.openInputStream(uri)
             ?: throw IllegalStateException("Cannot open URI")
-        val tempFile = File.createTempFile("upload_", ".jpg", context.cacheDir)
+        val tempFile = File.createTempFile("upload_", extension, context.cacheDir)
         FileOutputStream(tempFile).use { output ->
             inputStream.copyTo(output)
         }