feat: auth scaffold, notifications inbox, resources CRUD, vitest baseline, typed API client

Auth
- ~/lib/session.ts: Session type + loadSession/signIn/signOut/hasSession,
  reactive useSession hook (mock backend; replace fetch calls with your
  real auth endpoint when ready)
- routes/login.tsx: form with email/password (mock-validated), bounces
  to ?next= on success
- AppShell: redirects to /login when no session; account-menu Sign out
  now actually signs out; live session.name/email used for the appbar
  avatar (falls back to profile)

Notifications
- ~/lib/notifications.ts: persistent inbox with kinds (info/success/
  warning/error), unreadCount, markRead, markAllRead, dismiss,
  dismissAll; seedIfEmpty for a friendly first-run
- AppShell bell: 320px popover with badge, kind dots, per-row open
  (navigates to href) and dismiss; Mark all read + Clear actions
- Hidden NotificationDispatcher in AppShell so the action bus can
  create real notifications via fill notif-title / notif-body /
  notif-kind / notif-href + click notif-create

Data layer
- ~/lib/api.ts: typed apiFetch<T> + api.get/post/put/patch/del,
  auto-attaches the session token, throws structured ApiError, signs
  out on 401
- ~/lib/resources.ts: example domain entity (CRUD) backed by
  localStorage today; each call is a 1:1 swap for api.get/post/put/del
- routes/resources.tsx: real working table — search, add, inline
  status edit, delete; seeded demo rows on first load

Tests
- vitest + jsdom + @testing-library/react + @testing-library/jest-dom
  + vite-tsconfig-paths installed
- vitest.config.ts (jsdom, globals, ~ aliases via tsconfig-paths)
- vitest.setup.ts (RTL cleanup + localStorage clear between tests)
- app/lib/session.test.ts and resources.test.ts as starter coverage
- npm test / npm run test:watch scripts

UI Control catalog
- Login form, resources CRUD, notifications inbox, and the hidden
  notif-bridge ids tagged so the assistant can drive every new surface

Threads
- ThreadMessage now carries optional agentId so per-message authorship
  survives persona switches and handoffs

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/routes/assistant.tsx

@@ -53,6 +53,16 @@ Agents settings: settings-agent-new, settings-agent-reset, settings-agent-activa
 Assistant agent picker: assistant-agent (dropdown — click to switch persona)
 Assistant page: assistant-model, assistant-agent, assistant-thread, assistant-thread-new, assistant-thread-switch-<id>, assistant-thread-rename-<id>, assistant-thread-delete-<id>, assistant-ui-control, assistant-compact, assistant-restore-compact, assistant-regenerate, assistant-continue, assistant-show-prompt, assistant-copy-md, assistant-export-md, assistant-save-library, assistant-compare, assistant-handoff-<id>, assistant-stop, assistant-clear, assistant-retry-probe, assistant-actions (open the kebab popover first to reveal the rest), assistant-voice (mic), assistant-msg-pin-<i>, assistant-msg-edit-<i>, assistant-msg-speak-<i>
 Library page: library-search, library-open-<id>, library-copy-<id>, library-download-<id>, library-delete-<id>
+Resources page: resources-search, resources-new-name, resources-create, resources-status-<id>, resources-delete-<id>
+Login page: login-email, login-password, login-submit
+Notifications popover: appbar-notifications (open), notif-mark-all-read, notif-clear, notif-open-<id>, notif-dismiss-<id>
+Create a notification (hidden bridge — always available, even when not visible): fill the four hidden inputs, then click the submit button. Recipe:
+  fill notif-title "Reminder"
+  fill notif-body "Take a 5-minute break"
+  fill notif-kind "info"           # info | success | warning | error
+  fill notif-href "/library"       # optional, omit if no link
+  click notif-create
+Use this any time the user asks you to remind them, leave a note, flag something, or queue an item — drop a notification.
 
 Example — User: "Go to settings and set the response cap to 1024" →
 "On it.
@@ -391,11 +401,18 @@ function AssistantSurface({
   })
 
   // Persist conversation back into the active thread.
+  // Preserve any agentId already stamped on prior messages, and stamp newly
+  // appended assistant messages with the *currently active* agent.
   useEffect(() => {
     if (isStreaming) return
+    const stamped: ThreadMessage[] = messages.map((m, i) => {
+      const prior = thread.messages[i]
+      if (m.role === "user") return { role: "user", content: m.content }
+      const agentId = prior?.agentId ?? activeAgentId
+      return { role: "assistant", content: m.content, agentId }
+    })
     updateThread(thread.id, {
-      messages: messages as ThreadMessage[],
-      // Auto-title from the first user message if the thread is still untitled.
+      messages: stamped,
       ...(thread.title === "New conversation" &&
       messages[0]?.role === "user"
         ? { title: deriveTitleFromFirstMessage(messages[0].content) }
@@ -667,9 +684,20 @@ function AssistantSurface({
           { maxTokens: 220 },
         )
         const note = `🤝 **Handoff: ${activeAgent.name} → ${target.name}**\n\n${briefing.trim()}`
+        // Stamp the existing thread messages (preserve their authorship) and
+        // attribute the handoff note itself to the OUTGOING agent.
+        const stamped: ThreadMessage[] = messages.map((m, i) => {
+          const prior = thread.messages[i]
+          if (m.role === "user") return { role: "user", content: m.content }
+          return {
+            role: "assistant",
+            content: m.content,
+            agentId: prior?.agentId ?? activeAgent.id,
+          }
+        })
         const next: ThreadMessage[] = [
-          ...(messages as ThreadMessage[]),
-          { role: "assistant", content: note },
+          ...stamped,
+          { role: "assistant", content: note, agentId: activeAgent.id },
         ]
         updateThread(thread.id, { messages: next, agentId: target.id })
         saveActiveAgentId(target.id)
@@ -832,14 +860,37 @@ function AssistantSurface({
                 !messages.slice(i + 1).some((x) => x.role === "user")
               const isEditing = editingIndex === i
               const isUser = m.role === "user"
+              const msgAgentId =
+                !isUser
+                  ? thread.messages[i]?.agentId ?? activeAgent?.id
+                  : undefined
+              const msgAgent = msgAgentId
+                ? agents.find((a) => a.id === msgAgentId) ?? activeAgent
+                : undefined
               return (
                 <div
                   key={i}
                   className={
-                    "group flex flex-col " +
-                    (isUser ? "items-end" : "items-start")
+                    "group flex w-full items-start gap-2 " +
+                    (isUser ? "flex-row-reverse" : "flex-row")
                   }
                 >
+                  {!isUser && msgAgent && (
+                    <Avatar
+                      className="mt-5 size-7 shrink-0 ring-1 ring-border"
+                      title={`${msgAgent.name} — ${msgAgent.role}`}
+                    >
+                      <AvatarFallback
+                        style={{
+                          background: agentTint(msgAgent.id),
+                          color: "var(--primary-foreground)",
+                        }}
+                        className="text-[11px] font-semibold"
+                      >
+                        {agentInitials(msgAgent.name)}
+                      </AvatarFallback>
+                    </Avatar>
+                  )}
                   <div
                     className={
                       "flex max-w-[80%] flex-col " +
@@ -848,8 +899,15 @@ function AssistantSurface({
                   >
                     <div className="mb-0.5 flex items-center gap-1.5 px-1">
                       <span className="text-xs font-medium text-muted-foreground">
-                        {isUser ? "You" : "Assistant"}
+                        {isUser
+                          ? "You"
+                          : (msgAgent?.name ?? "Assistant")}
                       </span>
+                      {!isUser && msgAgent && (
+                        <span className="text-[10px] text-muted-foreground/70">
+                          · {msgAgent.role}
+                        </span>
+                      )}
                       {isPinned && (
                         <Pin className="size-3 fill-primary text-primary" />
                       )}
@@ -1368,10 +1426,24 @@ function AssistantSurface({
           responseBudget={responseBudget}
           onClose={() => setCompareOpen(false)}
           onAppend={(agentName, content) => {
+            const speaker = agents.find((a) => a.name === agentName)
             const note = `🪞 **${agentName} says:**\n\n${content}`
+            const stamped: ThreadMessage[] = messages.map((m, i) => {
+              const prior = thread.messages[i]
+              if (m.role === "user") return { role: "user", content: m.content }
+              return {
+                role: "assistant",
+                content: m.content,
+                agentId: prior?.agentId ?? activeAgent?.id,
+              }
+            })
             const next: ThreadMessage[] = [
-              ...(messages as ThreadMessage[]),
-              { role: "assistant", content: note },
+              ...stamped,
+              {
+                role: "assistant",
+                content: note,
+                agentId: speaker?.id ?? activeAgent?.id,
+              },
             ]
             updateThread(thread.id, { messages: next })
             setActionLog(`Appended ${agentName}'s reply to the thread.`)