feat: add session sharing types, API client, and utilities

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/api/sessions.ts

@@ -1,5 +1,5 @@
 import apiClient from './client'
-import type { Session, SessionCreate, SessionUpdate, SessionExport, SaveAsTreeRequest, SaveAsTreeResponse, SessionComplete, RedactionSummary } from '@/types'
+import type { Session, SessionCreate, SessionUpdate, SessionExport, SaveAsTreeRequest, SaveAsTreeResponse, SessionComplete, RedactionSummary, SessionShareCreate, SessionShare, SharedSessionView } from '@/types'
 
 export interface SessionListParams {
   page?: number
@@ -85,6 +85,26 @@ export const sessionsApi = {
     const response = await apiClient.post<SaveAsTreeResponse>(`/sessions/${id}/save-as-tree`, data)
     return response.data
   },
+
+  // Session Sharing
+  async createShare(sessionId: string, data: SessionShareCreate): Promise<SessionShare> {
+    const response = await apiClient.post<SessionShare>(`/sessions/${sessionId}/shares`, data)
+    return response.data
+  },
+
+  async listMyShares(): Promise<SessionShare[]> {
+    const response = await apiClient.get<SessionShare[]>('/shares/my-shares')
+    return response.data
+  },
+
+  async revokeShare(shareId: string): Promise<void> {
+    await apiClient.delete(`/shares/${shareId}`)
+  },
+
+  async getSharedSession(shareToken: string): Promise<SharedSessionView> {
+    const response = await apiClient.get<SharedSessionView>(`/share/${shareToken}`)
+    return response.data
+  },
 }
 
 export default sessionsApi

frontend/src/lib/sessionShare.ts

@@ -0,0 +1,27 @@
+import type { SessionShare } from '@/types'
+
+/**
+ * Build the full share URL from a SessionShare object.
+ * Uses share.share_url if present, otherwise constructs from token.
+ */
+export function buildSessionShareUrl(share: SessionShare): string {
+  if (share.share_url) return share.share_url
+  return `${window.location.origin}/share/${share.share_token}`
+}
+
+/**
+ * Filter shares to only those belonging to a specific session.
+ */
+export function filterSharesForSession(shares: SessionShare[], sessionId: string): SessionShare[] {
+  return shares.filter(s => s.session_id === sessionId && s.is_active)
+}
+
+/**
+ * Get the most recent active share for a given session.
+ * Returns null if no active shares exist.
+ */
+export function getLatestActiveShareForSession(shares: SessionShare[], sessionId: string): SessionShare | null {
+  const sessionShares = filterSharesForSession(shares, sessionId)
+  if (sessionShares.length === 0) return null
+  return sessionShares.sort((a, b) => new Date(b.created_at).getTime() - new Date(a.created_at).getTime())[0]
+}

frontend/src/types/session.ts

@@ -125,3 +125,45 @@ export interface SaveAsTreeResponse {
   tree_name: string
   message: string
 }
+
+// Session Sharing
+export type SessionShareVisibility = 'public' | 'account'
+
+export interface SessionShareCreate {
+  visibility: SessionShareVisibility
+  share_name?: string
+  expires_at?: string // ISO datetime string
+}
+
+export interface SessionShare {
+  id: string
+  session_id: string
+  account_id: string
+  share_token: string
+  share_name: string | null
+  visibility: SessionShareVisibility
+  created_by: string
+  created_at: string
+  updated_at: string
+  expires_at: string | null
+  view_count: number
+  last_viewed_at: string | null
+  is_active: boolean
+  share_url: string | null
+}
+
+export interface SharedSessionView {
+  session_id: string
+  tree_name: string
+  tree_description: string | null
+  tree_structure: Record<string, unknown>
+  path_taken: string[]
+  decisions: DecisionRecord[]
+  custom_steps: CustomStep[]
+  started_at: string
+  completed_at: string | null
+  ticket_number: string | null
+  client_name: string | null
+  share_name: string | null
+  visibility: SessionShareVisibility
+}