Generate webHtmlApp's strings, collapse a redundant string key

Strings.kt is now generated at build time (:webHtmlApp:generateStrings,
in webHtmlApp/build.gradle.kts) by parsing shared's strings.xml
directly, rather than a hand-maintained duplicate that could silently
drift from it. Names are mechanical camelCase of the XML key, so a few
call sites got more verbose (e.g. moveUp -> moveCurrencyUpContentDescription)
in exchange for zero manual sync. Only covers the base English locale.

Also collapses currency_option_label_local into currency_option_label:
the two had identical English text and existed only as a hook for a
future translation to phrase the user's own currency differently, which
no locale currently does. Removes the info.code == localeCurrencyCode
branching (and the now-pointless localeCurrencyCode parameter/field) from
all three UI implementations - PriceScreen.kt, CurrencyPickerSheet.swift,
and HtmlCurrencyPicker.kt - plus IosConverterState.localeCurrencyCode,
which existed solely to feed that branch on the Swift side.

Fixes a real regression surfaced while verifying the above by actually
building the Xcode project (not done since currencyFlagEmoji() gained
its supportsFlagEmoji parameter): Kotlin/Native doesn't generate
default-parameter overloads for Swift/ObjC-exported functions, so both
Swift call sites needed the argument passed explicitly, via the correct
exported facade name for an expect/actual pair - the actual file's
(SystemCurrencies_appleKt), not the common one (SystemCurrenciesKt).

Also drops "(DOM)" from webHtmlApp's page title.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

webHtmlApp/build.gradle.kts

@@ -1,9 +1,92 @@
+import org.w3c.dom.Element
+import javax.xml.parsers.DocumentBuilderFactory
+
 plugins {
     alias(libs.plugins.kotlinMultiplatform)
     alias(libs.plugins.composeMultiplatform)
     alias(libs.plugins.composeCompiler)
 }
 
+// webHtmlApp can't use moko-resources' Compose integration (stringResource()) without pulling
+// in compose.foundation/ui transitively - exactly what this module exists to avoid (see
+// AGENTS.md's "Module layout"). Generating a plain Strings.kt from the same strings.xml moko
+// reads keeps that file as the single source of truth without a manually maintained, silently
+// driftable duplicate. Only covers the base (English) locale - see AGENTS.md.
+val stringsXmlFile = rootProject.file("shared/src/commonMain/moko-resources/base/strings.xml")
+
+val generateStrings by tasks.registering {
+    val outputDir = layout.buildDirectory.dir("generated/strings")
+    // Captured as a plain local (rather than read from the doLast closure directly) so the task
+    // action doesn't hold a reference to the build script object itself, which the configuration
+    // cache refuses to serialize.
+    val xmlFile = stringsXmlFile
+    inputs.file(xmlFile)
+    outputs.dir(outputDir)
+
+    doLast {
+        val document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(xmlFile)
+        val stringNodes = document.getElementsByTagName("string")
+        val placeholderPattern = Regex("""%(\d+)\$([sd])""")
+
+        fun String.toCamelCase(): String = split("_").mapIndexed { index, word ->
+            if (index == 0) word else word.replaceFirstChar { it.uppercase() }
+        }.joinToString("")
+
+        val source = buildString {
+            appendLine("// GENERATED FILE - do not edit directly.")
+            appendLine("// Regenerated by :webHtmlApp:generateStrings from")
+            appendLine("// shared/src/commonMain/moko-resources/base/strings.xml - edit that file instead.")
+            appendLine("package xyz.tyiu.satsprice")
+            appendLine()
+            appendLine("object Strings {")
+            for (i in 0 until stringNodes.length) {
+                val element = stringNodes.item(i) as Element
+                val propertyName = element.getAttribute("name").toCamelCase()
+                // moko/Android string-resource XML escapes a literal apostrophe as \' inside the
+                // (unquoted) text content - unescape that before anything else so it doesn't get
+                // mistaken for a Kotlin escape sequence below.
+                val rawValue = element.textContent.replace("\\'", "'")
+
+                val placeholders = placeholderPattern.findAll(rawValue)
+                    .map { it.groupValues[1].toInt() to it.groupValues[2] }
+                    .distinct()
+                    .sortedBy { it.first }
+                    .toList()
+
+                // Swap each %N$s/%N$d placeholder for a control-character sentinel first, so the
+                // literal '$' in "%1$s" itself doesn't get caught by the blanket '$' -> "\$"
+                // escaping below - then escape, then turn the sentinels into "${argN}".
+                var withSentinels = rawValue
+                for ((index, _) in placeholders) {
+                    withSentinels = withSentinels.replace(Regex("""%$index\$[sd]"""), "
$index
")
+                }
+                val escaped = withSentinels
+                    .replace("\\", "\\\\")
+                    .replace("\"", "\\\"")
+                    .replace("$", "\\$")
+                var templateBody = escaped
+                for ((index, _) in placeholders) {
+                    templateBody = templateBody.replace("
$index
", "\${arg$index}")
+                }
+
+                if (placeholders.isEmpty()) {
+                    appendLine("    const val $propertyName: String = \"$templateBody\"")
+                } else {
+                    val params = placeholders.joinToString(", ") { (index, type) ->
+                        "arg$index: ${if (type == "d") "Int" else "String"}"
+                    }
+                    appendLine("    fun $propertyName($params): String = \"$templateBody\"")
+                }
+            }
+            appendLine("}")
+        }
+
+        val outputFile = outputDir.get().file("xyz/tyiu/satsprice/Strings.kt").asFile
+        outputFile.parentFile.mkdirs()
+        outputFile.writeText(source)
+    }
+}
+
 // Compose HTML (org.jetbrains.compose.html:html-core) only publishes js and jvm target
 // variants as of Compose Multiplatform 1.11.1 - no wasmJs artifact exists yet, unlike the
 // Skia-based Compose Multiplatform UI toolkit webApp uses (which targets both). So this
@@ -15,11 +98,14 @@ kotlin {
     }
 
     sourceSets {
-        commonMain.dependencies {
-            implementation(project(":shared"))
+        commonMain {
+            kotlin.srcDir(generateStrings)
+            dependencies {
+                implementation(project(":shared"))
 
-            implementation(libs.compose.runtime)
-            implementation(libs.compose.html.core)
+                implementation(libs.compose.runtime)
+                implementation(libs.compose.html.core)
+            }
         }
     }
 }