feat: add offline casting flow and local history sessions

Replace the development fixture shell with method intro, question, coin entry, and result screens. Persist locked casts in private Room storage under the save policy, and document remaining P2 content and P4 history-list gaps.

Co-authored-by: Cursor <cursoragent@cursor.com>

build.gradle.kts

@@ -61,6 +61,12 @@ val verifyDependencyLicenseManifest = registerNodeVerificationTask(
     script = "scripts/verify-dependency-licenses.mjs",
 )
 
+val verifyLocalDataBoundary = registerNodeVerificationTask(
+    name = "verifyLocalDataBoundary",
+    description = "Locks down offline permissions and excludes local records from backup and transfer.",
+    script = "scripts/verify-local-data-boundary.mjs",
+)
+
 tasks.register("verifyLocal") {
     group = LifecycleBasePlugin.VERIFICATION_GROUP
     description = "Runs every environment-independent local quality gate."
@@ -76,6 +82,7 @@ tasks.register("verifyLocal") {
         verifyContentContract,
         spotlessCheck,
         verifyDependencyLicenseManifest,
+        verifyLocalDataBoundary,
     )
 }