feat(schedule): add absolute-time reminders

packages/host/apiproxy/src/api/rpc.schema.ts

@@ -36,7 +36,25 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
   z.object({ code: z.literal('cancelled'), message: z.string(), details: z.object({}) }),
   z.object({ code: z.literal('session-not-found'), message: z.string(), details: z.object({ sessionId: z.string() }) }),
   z.object({ code: z.literal('model-unavailable'), message: z.string(), details: z.object({ provider: z.string(), model: z.string() }) }),
-  z.object({ code: z.literal('session-conflict'), message: z.string(), details: z.object({ sessionId: z.string(), requestedCwd: z.string(), existingCwd: z.string().optional() }) }),
+  z.object({
+    code: z.literal('session-conflict'),
+    message: z.string(),
+    details: z.object({
+      sessionId: z.string(),
+      requestedCwd: z.string(),
+      existingCwd: z.string().optional(),
+      requestedTimeZone: z.string(),
+      existingTimeZone: z.string().optional(),
+    }),
+  }),
+  z.object({
+    code: z.literal('invalid-time-zone'),
+    message: z.string(),
+    details: z.object({
+      field: z.union([z.literal('timeZone'), z.literal('clientTimeZone')]),
+      value: z.union([z.string(), z.null()]),
+    }),
+  }),
   z.object({ code: z.literal('workspace-attach-failed'), message: z.string(), details: z.object({ sessionId: z.string(), workspaceId: z.string() }) }),
   z.object({ code: z.literal('workspace-not-found'), message: z.string(), details: z.object({ workspaceId: z.string() }) }),
   z.object({ code: z.literal('workspace-invalid-path'), message: z.string(), details: z.object({ path: z.string() }) }),

packages/host/apiproxy/src/api/rpc.ts

@@ -34,7 +34,14 @@ export interface RpcErrorDetailsMap {
   'cancelled': {}
   'session-not-found': { sessionId: SessionId }
   'model-unavailable': { provider: string; model: string }
-  'session-conflict': { sessionId: SessionId; requestedCwd: string; existingCwd?: string }
+  'session-conflict': {
+    sessionId: SessionId
+    requestedCwd: string
+    existingCwd?: string
+    requestedTimeZone: string
+    existingTimeZone?: string
+  }
+  'invalid-time-zone': { field: 'timeZone' | 'clientTimeZone'; value: string | null }
   'workspace-attach-failed': { sessionId: SessionId; workspaceId: string }
   'workspace-not-found': { workspaceId: string }
   'workspace-invalid-path': { path: string }

packages/host/apiproxy/src/api/sessions.schema.ts

@@ -100,6 +100,7 @@ export const sessionCreateRequestSchema = z.object({
   workspaceId: workspaceIdSchema.optional(),
   cwd: z.string().optional(),
   sessionId: sessionIdSchema.optional(),
+  timeZone: z.string().optional(),
 }).refine(
   payload => payload.workspaceId === undefined || payload.cwd === undefined,
   { message: 'session.create accepts workspaceId or cwd, not both' },
@@ -251,6 +252,7 @@ export const sessionPromptRequestSchema = z.object({
   sessionId: sessionIdSchema,
   mode: z.union([z.literal('queue'), z.literal('steer')]),
   content: z.array(contentBlockSchema),
+  clientTimeZone: z.string().optional(),
 }) as unknown as z.ZodType<RequestPayload<'session.prompt'>>
 
 /** session.prompt response value (the command slot appears only when the prompt dispatched a slash command). */

packages/host/apiproxy/src/api/sessions.ts

@@ -22,7 +22,7 @@ declare module '@deepseek-ai/dsh-llm' {
      * echoed provisional message with the event stream). kind stays `'user'` — the model face
      * carries no transport vocabulary; rpcId is an extra durable-JSON field passed back to the client with the event.
      */
-    'user-rpc': { kind: 'user'; rpcId: RpcId }
+    'user-rpc': { kind: 'user'; rpcId: RpcId; clientTimeZone: string }
   }
 }
 
@@ -204,12 +204,19 @@ export interface SessionsApi {
   /**
    * Creates a real session and its idle agent. At most one of `workspaceId` /
    * `cwd` is accepted; an omitted project uses the Host cwd. A caller may
-   * preallocate `sessionId`: retries with the same id and cwd return the same
-   * session, while a different cwd fails with `session-conflict`. Workspace
+   * preallocate `sessionId`: retries with the same id, cwd, and canonical time
+   * zone return the same session, while a different owned identity fails with
+   * `session-conflict`. A headerless persisted session remains compatible with
+   * the same cwd but never absorbs the request zone. Workspace
    * creation attaches the session after publication; an attach failure
    * returns `workspace-attach-failed` with the published session id.
    */
-  create(request: RpcRequest<{ workspaceId?: WorkspaceId; cwd?: string; sessionId?: SessionId }>):
+  create(request: RpcRequest<{
+    workspaceId?: WorkspaceId
+    cwd?: string
+    sessionId?: SessionId
+    timeZone?: string
+  }>):
   Promise<RpcResponse<{ sessionId: SessionId }>>
 
   /**
@@ -289,7 +296,12 @@ export interface SessionsApi {
   Promise<RpcResponse<{ sessionId: SessionId }>>
 
   /** Sends a message to an ordinary session Agent. Session-backed subagents reject with `agent-busy` and use `subagent.prompt`. */
-  prompt(request: RpcRequest<{ sessionId: SessionId; mode: 'queue' | 'steer'; content: ContentBlock[] }>):
+  prompt(request: RpcRequest<{
+    sessionId: SessionId
+    mode: 'queue' | 'steer'
+    content: ContentBlock[]
+    clientTimeZone?: string
+  }>):
   Promise<RpcResponse<{ accepted: true; command?: { kind: 'success'; text?: string } }>>
 
   /**