feat(rhema-code): add the colors setting with four palettes

The stored `colors` key names a palette — rhema (the default,
Jadeite), aquamarine, black-and-white, or dracula — and the
Appearance page of /settings cycles it live, like the theme and
icon toggles beside it. Each palette carries a dark and a light
appearance under the existing `theme` key; dracula's light side is
derived, the official palette ships only dark.

The appearance decision moves off token comparison: Theme now
answers is_dark() from the ground/text luminance, so palettes
beyond the original two get the right per-profile fallback tones.

android/settings.gradle.kts

@@ -0,0 +1,24 @@
+pluginManagement {
+    repositories {
+        google {
+            content {
+                includeGroupByRegex("com\\.android.*")
+                includeGroupByRegex("com\\.google.*")
+                includeGroupByRegex("androidx.*")
+            }
+        }
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.name = "rhema-android"
+include(":app")