feat: add GhostSite model and /site/ API endpoint

Add GhostSite data class for Ghost CMS site metadata (title, description,
logo, icon, accent color, URL, version, locale). Add getSite() endpoint
to GhostApiService. Include unit tests for Gson deserialization and
version parsing.

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

@@ -1,5 +1,6 @@
 package com.swoosh.microblog.data.api
 
+import com.swoosh.microblog.data.model.GhostSite
 import com.swoosh.microblog.data.model.PostWrapper
 import com.swoosh.microblog.data.model.PostsResponse
 import okhttp3.MultipartBody
@@ -37,6 +38,9 @@ interface GhostApiService {
         @Path("id") id: String
     ): Response<Unit>
 
+    @GET("ghost/api/admin/site/")
+    suspend fun getSite(): Response<GhostSite>
+
     @GET("ghost/api/admin/users/me/")
     suspend fun getCurrentUser(): Response<UsersResponse>
 

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

@@ -0,0 +1,12 @@
+package com.swoosh.microblog.data.model
+
+data class GhostSite(
+    val title: String?,
+    val description: String?,
+    val logo: String?,
+    val icon: String?,
+    val accent_color: String?,
+    val url: String?,
+    val version: String?,
+    val locale: String?
+)

app/src/test/java/com/swoosh/microblog/data/model/SiteModelsTest.kt

@@ -0,0 +1,129 @@
+package com.swoosh.microblog.data.model
+
+import com.google.gson.Gson
+import org.junit.Assert.*
+import org.junit.Test
+
+class SiteModelsTest {
+
+    private val gson = Gson()
+
+    @Test
+    fun `deserialize full site response`() {
+        val json = """
+        {
+            "title": "My Ghost Blog",
+            "description": "A blog about things",
+            "logo": "https://example.com/logo.png",
+            "icon": "https://example.com/icon.png",
+            "accent_color": "#ff1a75",
+            "url": "https://example.com/",
+            "version": "5.82.0",
+            "locale": "en"
+        }
+        """.trimIndent()
+
+        val site = gson.fromJson(json, GhostSite::class.java)
+
+        assertEquals("My Ghost Blog", site.title)
+        assertEquals("A blog about things", site.description)
+        assertEquals("https://example.com/logo.png", site.logo)
+        assertEquals("https://example.com/icon.png", site.icon)
+        assertEquals("#ff1a75", site.accent_color)
+        assertEquals("https://example.com/", site.url)
+        assertEquals("5.82.0", site.version)
+        assertEquals("en", site.locale)
+    }
+
+    @Test
+    fun `deserialize site response with null fields`() {
+        val json = """
+        {
+            "title": "Minimal Blog",
+            "url": "https://minimal.ghost.io/"
+        }
+        """.trimIndent()
+
+        val site = gson.fromJson(json, GhostSite::class.java)
+
+        assertEquals("Minimal Blog", site.title)
+        assertNull(site.description)
+        assertNull(site.logo)
+        assertNull(site.icon)
+        assertNull(site.accent_color)
+        assertEquals("https://minimal.ghost.io/", site.url)
+        assertNull(site.version)
+        assertNull(site.locale)
+    }
+
+    @Test
+    fun `version parsing extracts major version`() {
+        val site = GhostSite(
+            title = "Test",
+            description = null,
+            logo = null,
+            icon = null,
+            accent_color = null,
+            url = null,
+            version = "5.82.0",
+            locale = null
+        )
+
+        val majorVersion = site.version?.split(".")?.firstOrNull()?.toIntOrNull()
+        assertEquals(5, majorVersion)
+    }
+
+    @Test
+    fun `version parsing handles old version`() {
+        val site = GhostSite(
+            title = "Old Blog",
+            description = null,
+            logo = null,
+            icon = null,
+            accent_color = null,
+            url = null,
+            version = "4.48.9",
+            locale = null
+        )
+
+        val majorVersion = site.version?.split(".")?.firstOrNull()?.toIntOrNull()
+        assertEquals(4, majorVersion)
+        assertTrue((majorVersion ?: 0) < 5)
+    }
+
+    @Test
+    fun `version parsing handles null version`() {
+        val site = GhostSite(
+            title = "No Version",
+            description = null,
+            logo = null,
+            icon = null,
+            accent_color = null,
+            url = null,
+            version = null,
+            locale = null
+        )
+
+        val majorVersion = site.version?.split(".")?.firstOrNull()?.toIntOrNull()
+        assertNull(majorVersion)
+    }
+
+    @Test
+    fun `serialize and deserialize round trip`() {
+        val original = GhostSite(
+            title = "Round Trip Blog",
+            description = "Testing serialization",
+            logo = "https://example.com/logo.png",
+            icon = "https://example.com/icon.png",
+            accent_color = "#15171a",
+            url = "https://example.com/",
+            version = "5.82.0",
+            locale = "pl"
+        )
+
+        val json = gson.toJson(original)
+        val deserialized = gson.fromJson(json, GhostSite::class.java)
+
+        assertEquals(original, deserialized)
+    }
+}