Add reader font size setting, rewrite paywall-avoidance settings copy

Font size was hardcoded at 18px in ReaderWebView's injected CSS. Added
a DataStore-backed setting (Settings.readerFontSizePx, 14-28px range)
with a slider in Settings, threaded through ReaderScreen/ReaderContent
into wrapReaderHtml. The reload-tracking key in ReaderContent's
AndroidView now includes font size alongside content, so changing it
and returning to an already-open article picks up the new size without
reloading on every unrelated recomposition (matches the existing
comment there about avoiding scroll-position jank).

Rewrote the Settings screen's paywall note -- it read as defensive
throat-clearing about what the app won't do. Restated as what it's
actually for: avoiding tracking, manipulation, and junk fees, with
reader mode pulling up anything findable by search anyway.

Regenerated the detekt baseline: ReaderContent's pre-existing
LongMethod/LongParameterList/CyclomaticComplexMethod findings are
keyed by exact function signature text, and adding the fontSizePx
parameter changed that text, invalidating the old baseline entries.
The underlying debt (a 300+ line, 9-now-10-parameter composable)
predates this change and isn't what this commit is about.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018AwnALZL6bD4VBtATDVv3B

4 files changed, 75 insertions, 15 deletions

diff --git a/app/src/main/java/org/terst/feedreader/data/Settings.kt b/app/src/main/java/org/terst/feedreader/data/Settings.kt
index 2e7eaae..be3e809 100644
--- a/app/src/main/java/org/terst/feedreader/data/Settings.kt
+++ b/app/src/main/java/org/terst/feedreader/data/Settings.kt
@@ -28,8 +28,16 @@ private object SettingsKeys {
     val LAST_FETCH_AT = longPreferencesKey("last_fetch_at")
     val LAST_FETCH_NEW_ARTICLES = intPreferencesKey("last_fetch_new_articles")
     val LAST_ACKNOWLEDGED_FETCH_AT = longPreferencesKey("last_acknowledged_fetch_at")
+    val READER_FONT_SIZE_PX = intPreferencesKey("reader_font_size_px")
 }
 
+// Matches the size ReaderWebView hardcoded before this setting existed, so an upgrading
+// user's reader looks exactly the same until they deliberately change it.
+const val DEFAULT_READER_FONT_SIZE_PX = 18
+private const val READER_FONT_SIZE_MIN_PX = 14
+private const val READER_FONT_SIZE_MAX_PX = 28
+val READER_FONT_SIZE_RANGE_PX = READER_FONT_SIZE_MIN_PX..READER_FONT_SIZE_MAX_PX
+
 /** Stash connection settings, configured on the Settings screen. Both blank until set. */
 class Settings(private val context: Context) {
     val stashBaseUrl: Flow<String> =
@@ -109,4 +117,15 @@ class Settings(private val context: Context) {
     suspend fun acknowledgeFetch(at: Long) {
         context.settingsDataStore.edit { prefs -> prefs[SettingsKeys.LAST_ACKNOWLEDGED_FETCH_AT] = at }
     }
+
+    val readerFontSizePx: Flow<Int> =
+        context.settingsDataStore.data.map { it[SettingsKeys.READER_FONT_SIZE_PX] ?: DEFAULT_READER_FONT_SIZE_PX }
+
+    suspend fun readerFontSizePxNow(): Int = readerFontSizePx.first()
+
+    suspend fun setReaderFontSizePx(px: Int) {
+        context.settingsDataStore.edit { prefs ->
+            prefs[SettingsKeys.READER_FONT_SIZE_PX] = px.coerceIn(READER_FONT_SIZE_RANGE_PX.first, READER_FONT_SIZE_RANGE_PX.last)
+        }
+    }
 }
diff --git a/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt b/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt
index 3c3ab66..a89052c 100644
--- a/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt
+++ b/app/src/main/java/org/terst/feedreader/ui/ReaderScreen.kt
@@ -41,6 +41,7 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -56,6 +57,7 @@ import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import org.terst.feedreader.data.AppDatabase
 import org.terst.feedreader.data.ArticleEntity
+import org.terst.feedreader.data.DEFAULT_READER_FONT_SIZE_PX
 import org.terst.feedreader.data.FeedEntity
 import org.terst.feedreader.data.Settings
 import org.terst.feedreader.data.ensureStandaloneArticle
@@ -99,6 +101,7 @@ fun ReaderScreen(
     val db = remember { AppDatabase.get(context) }
     val settings = remember { Settings(context) }
     val scope = rememberCoroutineScope()
+    val fontSizePx by settings.readerFontSizePx.collectAsState(initial = DEFAULT_READER_FONT_SIZE_PX)
 
     var previousId by remember(articleId) { mutableStateOf<String?>(null) }
     var nextId by remember(articleId) { mutableStateOf<String?>(null) }
@@ -156,7 +159,8 @@ fun ReaderScreen(
         hasNext = nextId != null,
         onPrevious = ::goToPreviousArticle,
         onNext = ::goToNextArticle,
-        onNextKeepUnread = ::goToNextArticleKeepUnread
+        onNextKeepUnread = ::goToNextArticleKeepUnread,
+        fontSizePx = fontSizePx
     )
 }
 
@@ -171,7 +175,8 @@ private fun ReaderContent(
     hasNext: Boolean,
     onPrevious: () -> Unit,
     onNext: () -> Unit,
-    onNextKeepUnread: () -> Unit
+    onNextKeepUnread: () -> Unit,
+    fontSizePx: Int
 ) {
     val context = LocalContext.current
     val db = remember { AppDatabase.get(context) }
@@ -516,8 +521,11 @@ private fun ReaderContent(
                 // flipping while a Stash save is in flight. Reloading the WebView's HTML
                 // on those unrelated recompositions was resetting scroll position mid-swipe,
                 // which is what made scrolling feel unsmooth/janky. Track what's actually
-                // loaded and only reload when the content string itself changes.
-                val loadedContent = remember(articleId) { mutableStateOf<String?>(null) }
+                // loaded and only reload when the content string or font size actually
+                // changes -- fontSizePx is included deliberately (not just content) so
+                // changing it in Settings and coming back to an already-open article
+                // picks up the new size, without reloading on every unrelated recomposition.
+                val loadedKey = remember(articleId) { mutableStateOf<Pair<String?, Int>?>(null) }
                 AndroidView(
                     modifier = Modifier.fillMaxSize(),
                     factory = { ctx ->
@@ -532,14 +540,16 @@ private fun ReaderContent(
                             // to 0 on a page that hasn't grown tall enough yet.
                             onPageFinished = { webView -> webView.scrollTo(0, ReaderScrollPositions.get(articleId)) }
                         ).apply {
-                            loadDataWithBaseURL(baseUrl, wrapReaderHtml(content, article?.title, article?.publishedAt, article?.imageUrl), "text/html", "UTF-8", null)
-                            loadedContent.value = content
+                            val html = wrapReaderHtml(content, article?.title, article?.publishedAt, article?.imageUrl, fontSizePx)
+                            loadDataWithBaseURL(baseUrl, html, "text/html", "UTF-8", null)
+                            loadedKey.value = content to fontSizePx
                         }
                     },
                     update = { webView ->
-                        if (loadedContent.value != content) {
-                            webView.loadDataWithBaseURL(baseUrl, wrapReaderHtml(content, article?.title, article?.publishedAt, article?.imageUrl), "text/html", "UTF-8", null)
-                            loadedContent.value = content
+                        if (loadedKey.value != content to fontSizePx) {
+                            val html = wrapReaderHtml(content, article?.title, article?.publishedAt, article?.imageUrl, fontSizePx)
+                            webView.loadDataWithBaseURL(baseUrl, html, "text/html", "UTF-8", null)
+                            loadedKey.value = content to fontSizePx
                         }
                     },
                     // AndroidView does not destroy() the underlying WebView on its own --
diff --git a/app/src/main/java/org/terst/feedreader/ui/ReaderWebView.kt b/app/src/main/java/org/terst/feedreader/ui/ReaderWebView.kt
index 31fcb02..b13fc58 100644
--- a/app/src/main/java/org/terst/feedreader/ui/ReaderWebView.kt
+++ b/app/src/main/java/org/terst/feedreader/ui/ReaderWebView.kt
@@ -22,6 +22,7 @@ import androidx.compose.ui.unit.dp
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.compose.ui.window.Dialog
 import androidx.compose.ui.window.DialogProperties
+import org.terst.feedreader.data.DEFAULT_READER_FONT_SIZE_PX
 
 // In-memory only (process lifetime, not persisted to disk) -- scoped to "don't lose my
 // place if Next/Previous takes me away and back," not to surviving an app restart. A
@@ -344,7 +345,13 @@ private fun escapeHtml(text: String): String = text
 // on whatever heading Readability happened to keep in bodyContent (increasingly nothing --
 // see ReaderExtractor's <header> stripping) or on the top app bar's title, which truncates
 // to one line and was the only place a long title showed up before this.
-fun wrapReaderHtml(bodyContent: String, title: String? = null, publishedAt: Long? = null, imageUrl: String? = null): String {
+fun wrapReaderHtml(
+    bodyContent: String,
+    title: String? = null,
+    publishedAt: Long? = null,
+    imageUrl: String? = null,
+    fontSizePx: Int = DEFAULT_READER_FONT_SIZE_PX
+): String {
     val processedBody = replaceGenericIframes(replaceYouTubeIframes(bodyContent))
     // Some feeds' body HTML never embeds an image at all -- the only image they give us
     // is a separate RSS media:content/enclosure field (ArticleEntity.imageUrl), which
@@ -369,7 +376,7 @@ fun wrapReaderHtml(bodyContent: String, title: String? = null, publishedAt: Long
     return """
     <html><head><meta name="viewport" content="width=device-width, initial-scale=1">
     <style>
-    body { font-family: sans-serif; font-size: 18px; line-height: 1.5; padding: 16px;
+    body { font-family: sans-serif; font-size: ${fontSizePx}px; line-height: 1.5; padding: 16px;
            background-color: #121212; color: #e1e1e1; }
     h1.article-title { font-size: 1.5em; line-height: 1.3; margin: 0 0 0.6em 0; }
     p.article-date { font-size: 0.85em; color: #9aa0a6; margin: -0.4em 0 1em 0; }
diff --git a/app/src/main/java/org/terst/feedreader/ui/SettingsScreen.kt b/app/src/main/java/org/terst/feedreader/ui/SettingsScreen.kt
index 5f8eca7..966d36b 100644
--- a/app/src/main/java/org/terst/feedreader/ui/SettingsScreen.kt
+++ b/app/src/main/java/org/terst/feedreader/ui/SettingsScreen.kt
@@ -27,6 +27,7 @@ import androidx.compose.material3.ListItem
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Slider
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
@@ -44,13 +45,16 @@ import androidx.compose.ui.text.input.VisualTransformation
 import androidx.compose.ui.unit.dp
 import kotlinx.coroutines.launch
 import org.terst.feedreader.data.AppDatabase
+import org.terst.feedreader.data.DEFAULT_READER_FONT_SIZE_PX
 import org.terst.feedreader.data.FeedEntity
 import org.terst.feedreader.data.FilterAction
 import org.terst.feedreader.data.FilterRuleEntity
 import org.terst.feedreader.data.Net
+import org.terst.feedreader.data.READER_FONT_SIZE_RANGE_PX
 import org.terst.feedreader.data.Settings
 import org.terst.feedreader.stash.StashClient
 import org.terst.feedreader.stash.StashVerifyResult
+import kotlin.math.roundToInt
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -65,9 +69,11 @@ fun SettingsScreen(onBack: () -> Unit) {
     var stashKeyVisible by remember { mutableStateOf(false) }
     var isVerifyingStash by remember { mutableStateOf(false) }
     var stashStatus by remember { mutableStateOf<String?>(null) }
+    var fontSizePx by remember { mutableStateOf(DEFAULT_READER_FONT_SIZE_PX) }
     LaunchedEffect(Unit) {
         stashUrl = settings.stashBaseUrlNow()
         stashKey = settings.stashApiKeyNow()
+        fontSizePx = settings.readerFontSizePxNow()
     }
 
     var newRulePattern by remember { mutableStateOf("") }
@@ -98,10 +104,9 @@ fun SettingsScreen(onBack: () -> Unit) {
                     Text("FeeDreader", style = MaterialTheme.typography.titleMedium)
                     Spacer(modifier = Modifier.height(4.dp))
                     Text(
-                        "If a site paywalls its own feed, that's the site's call. But this reader " +
-                            "won't go out of its way to help a soft paywall block you from reading " +
-                            "something you already subscribed to get -- reader mode extracts the " +
-                            "article you were sent, nothing more, nothing sneaky.",
+                        "FeeDreader exists to avoid tracking, manipulation, and junk fees. If an " +
+                            "article's full text is something you could just as easily find with a " +
+                            "search, reader mode will pull it up here too.",
                         style = MaterialTheme.typography.bodyMedium
                     )
                 }
@@ -110,6 +115,25 @@ fun SettingsScreen(onBack: () -> Unit) {
 
             item {
                 Column(modifier = Modifier.padding(16.dp)) {
+                    Text("Reading", style = MaterialTheme.typography.titleMedium)
+                    Spacer(modifier = Modifier.height(8.dp))
+                    Text("Font size: ${fontSizePx}px", style = MaterialTheme.typography.bodyMedium)
+                    Slider(
+                        value = fontSizePx.toFloat(),
+                        onValueChange = { fontSizePx = it.roundToInt() },
+                        valueRange = READER_FONT_SIZE_RANGE_PX.first.toFloat()..READER_FONT_SIZE_RANGE_PX.last.toFloat(),
+                        steps = READER_FONT_SIZE_RANGE_PX.last - READER_FONT_SIZE_RANGE_PX.first - 1,
+                        // Persist on release, not on every onValueChange -- a drag crosses many
+                        // integer values in a fraction of a second, and there's no reason to hit
+                        // DataStore that often for a value nothing reads until the next article load.
+                        onValueChangeFinished = { scope.launch { settings.setReaderFontSizePx(fontSizePx) } }
+                    )
+                }
+                HorizontalDivider()
+            }
+
+            item {
+                Column(modifier = Modifier.padding(16.dp)) {
                     Text("Stash", style = MaterialTheme.typography.titleMedium)
                     Spacer(modifier = Modifier.height(8.dp))
                     OutlinedTextField(