feat(codex): share sessions across terminal and web

Use one native app-server for terminal, Web and phone clients while retaining the existing CLI and Runner lifecycle.

Synchronize native queues, permissions, question history and steering state; preserve explicit permission precedence and per-turn usage models. Resume inactive clear commands through Runner and reject independent child cold resumes.

Add shared-runtime regression tests, generated protocol fixtures and lifecycle documentation.

android/core/data/src/main/kotlin/app/hapi/data/api/ChatSessionApi.kt

@@ -42,6 +42,9 @@ interface AttachmentUploadApi {
  * and [AttachmentUploadApi] for the composer attachment flow (B-M3f).
  */
 interface ChatSessionApi : MessagesApi, AttachmentUploadApi {
+    /** Shared root creation; only the initiating client navigates. */
+    suspend fun clearConversation(sessionId: String): ResumeSessionResponse
+
     /** `POST /api/sessions/:id/messages` — `{ok:true}`; the row arrives via SSE. */
     suspend fun sendMessage(sessionId: String, message: SendMessageRequest)
 

android/core/data/src/main/kotlin/app/hapi/data/api/HapiApi.kt

@@ -280,6 +280,10 @@ class HapiApi internal constructor(
             QueuedStateRequest(localIds).toJsonBody(),
         )
 
+    /** `POST /api/sessions/:id/clear` — shared sessions; returns an independent root. */
+    override suspend fun clearConversation(sessionId: String): ResumeSessionResponse =
+        request("POST", url("api", "sessions", sessionId, "clear").build(), EMPTY_JSON)
+
     /** `POST /api/sessions/:id/abort` — active sessions only. */
     override suspend fun abortSession(sessionId: String) {
         request<Unit>("POST", url("api", "sessions", sessionId, "abort").build(), EMPTY_JSON)