Remove chat rooms and agent loops before storage migration (#3053)

* refactor(storage): remove chat rooms and agent loops

This is the prerequisite cleanup for the storage backend migration. Legacy wire schemas remain temporarily so mixed-version peers can still parse old messages, while daemon callers now use query-shaped AgentStorage methods that can map directly to SQL later.

* test(cli): remove retired chat and loop coverage

packages/protocol/src/chat/rpc-schemas.ts

@@ -1,6 +1,8 @@
 import { z } from "zod";
 import { ChatMessageSchema, ChatRoomDetailSchema } from "./types.js";
 
+// COMPAT(chatRooms): retained after the v0.3.0 feature removal; remove after 2027-02-09 when mixed-version peers no longer send legacy messages.
+
 export const ChatCreateRequestSchema = z.object({
   type: z.literal("chat/create"),
   requestId: z.string(),

packages/protocol/src/chat/types.ts

@@ -1,5 +1,7 @@
 import { z } from "zod";
 
+// COMPAT(chatRooms): retained after the v0.3.0 feature removal; remove after 2027-02-09 when mixed-version peers no longer send legacy messages.
+
 export const ChatRoomSchema = z.object({
   id: z.string(),
   name: z.string(),

packages/protocol/src/loop/rpc-schemas.ts

@@ -1,6 +1,8 @@
 import { z } from "zod";
 import { AgentProviderSchema } from "../provider-manifest.js";
 
+// COMPAT(agentLoops): retained after the v0.3.0 feature removal; remove after 2027-02-09 when mixed-version peers no longer send legacy messages.
+
 export const LoopLogEntrySchema = z.object({
   seq: z.number().int().positive(),
   timestamp: z.string(),