feat: implement PI core chat timeline

shared/coding-conversation-contracts.ts

@@ -315,6 +315,22 @@ export interface ConversationPatchEnvelope {
   patch: ConversationPatch;
 }
 
+export interface ConversationPatchBatchItem {
+  runId?: string;
+  seq: number;
+  at: number;
+  patch: ConversationPatch;
+}
+
+export interface CodingConversationPatchBatchEvent {
+  type: 'patch-batch';
+  conversationId: string;
+  workerGeneration: number;
+  fromSeq: number;
+  toSeq: number;
+  items: ConversationPatchBatchItem[];
+}
+
 export interface PrepareConversationInput {
   conversationId: string;
   projectId: string;

shared/coding-project-contracts.ts

@@ -0,0 +1,54 @@
+import type { ProjectAgentResponsibility, ProjectType } from './project-config';
+import type { ConversationModelState } from './coding-conversation-contracts';
+
+export interface CodingProjectSummary {
+  id: string;
+  name: string;
+  createdAt: string;
+  updatedAt: string;
+  lastOpenedAt: string;
+}
+
+export interface CodingProjectAgent extends ConversationModelState {
+  id: string;
+  avatarId: string;
+  avatarDataUrl?: string;
+  roleName: string;
+  name: string;
+  builtIn: boolean;
+  enabled: boolean;
+  skillIds: string[];
+  responsibility: ProjectAgentResponsibility;
+  prompt: string;
+  archivedAt: string | null;
+  pinned: boolean;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface CodingProjectConfig {
+  schemaVersion: 2;
+  projectType: ProjectType;
+  initialized: boolean;
+  agents: CodingProjectAgent[];
+  knowledgeDirectory: 'knowledge';
+  legacyConversationNotice: 'none' | 'pending' | 'acknowledged';
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface CodingConversationMetadata extends ConversationModelState {
+  id: string;
+  agentId: string;
+  title: string;
+  archivedAt: string | null;
+  unread: boolean;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface CodingProjectConfigSnapshot {
+  project: CodingProjectSummary;
+  config: CodingProjectConfig;
+  knowledgeFiles: string[];
+}