refactor: retire the session/title frame and the todos history rider from the wire

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

@@ -93,12 +93,6 @@ export const historyEntrySchema = z.object({
   view: toolEventViewSchema.optional(),
 }) satisfies z.ZodType<Wire<HistoryEntry>>
 
-/** One todo item of the tail page's session-level projection (the todo/write payload shape). */
-export const todoItemSchema = z.object({
-  content: z.string(),
-  status: z.union([z.literal('pending'), z.literal('in_progress'), z.literal('completed')]),
-})
-
 /**
  * Projection baseline passthrough: `values` stays a wide record — each value
  * was already parsed by its provider's own schema on the host side, and
@@ -110,11 +104,10 @@ export const sessionProjectionsBlockSchema = z.object({
   values: z.record(z.string(), z.unknown()),
 }) as unknown as z.ZodType<SessionProjectionsBlock>
 
-/** session.history response value (todos and projections ride the tail page only). */
+/** session.history response value (projections rides the tail page only). */
 export const sessionHistoryValueSchema = z.object({
   events: z.array(historyEntrySchema),
   hasMore: z.boolean(),
-  todos: z.array(todoItemSchema).optional(),
   projections: sessionProjectionsBlockSchema.optional(),
 }) satisfies z.ZodType<Wire<ResponseValue<'session.history'>>>