feat(feed): 랭킹 강조 텍스트 계약을 추가한다

app/src/main/java/kr/co/vividnext/sodalive/v2/widget/feed/FeedRankHighlight.kt

@@ -0,0 +1,13 @@
+package kr.co.vividnext.sodalive.v2.widget.feed
+
+data class FeedRankHighlight(
+    val start: Int,
+    val endExclusive: Int
+) {
+    fun coerceIn(text: CharSequence): FeedRankHighlight? {
+        if (text.isEmpty()) return null
+        val safeStart = start.coerceIn(0, text.length)
+        val safeEnd = endExclusive.coerceIn(0, text.length)
+        return if (safeStart < safeEnd) FeedRankHighlight(safeStart, safeEnd) else null
+    }
+}

app/src/main/java/kr/co/vividnext/sodalive/v2/widget/feed/FeedRankTextStyler.kt

@@ -0,0 +1,24 @@
+package kr.co.vividnext.sodalive.v2.widget.feed
+
+import android.text.SpannableString
+import android.text.Spanned
+import android.text.style.ForegroundColorSpan
+
+object FeedRankTextStyler {
+    fun style(
+        text: String,
+        highlightRanges: List<FeedRankHighlight>,
+        highlightColor: Int
+    ): SpannableString {
+        val spannable = SpannableString(text)
+        highlightRanges.mapNotNull { it.coerceIn(text) }.forEach { range ->
+            spannable.setSpan(
+                ForegroundColorSpan(highlightColor),
+                range.start,
+                range.endExclusive,
+                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE
+            )
+        }
+        return spannable
+    }
+}