feat(journal): conversational LLM-generated daily prep (replaces card)

The structured prep card was data-rich but voiceless. Replaced with an
LLM-generated conversational opener — same shape the briefing's compilation
slot had — that renders as a normal assistant chat bubble at the top of
the day's conversation.

Backend (services/journal_prep.py):
- Renamed generate_daily_prep -> gather_daily_sections (still pure data
  fetching, no LLM); kept the old name as a backwards-compat alias.
- New _generate_prep_prose: hands the gathered sections to generate_completion
  with a warm-conversational system prompt; returns prose. Falls back to a
  plain greeting if the LLM call fails or no model is configured.
- ensure_daily_prep_message now persists the prep as role='assistant' with
  the prose as content. Structured sections stay on msg_metadata for
  provenance. Auto-upgrades legacy system-role preps in place on next call.

Frontend:
- Drop the <article class="daily-prep"> structured block from JournalView.
  The prep is now just the first chat bubble — picks up the existing
  Illuminated Transcript styling automatically.
- Drop dayMessages / prepMessage / prepSections / asArray helpers — no
  longer needed.
- ChatMessage hideMessage filter: comment refined to clarify it only
  catches LEGACY system-role prep rows. Current preps are assistant-role
  and render normally.

Net effect: open /journal -> first thing you see is a warm assistant bubble
that talks about your day -> input bar below to reply.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/ChatMessage.vue

@@ -43,9 +43,10 @@ function formatMs(ms: number | null | undefined): string {
 
 const metadata = computed(() => (props.message.metadata ?? {}) as Record<string, unknown>);
 
-// Hide daily-prep system messages — they're rendered separately as a structured
-// card in JournalView. Without this filter they render as a flat unstyled block
-// inside the chat (no .role-system bubble styling exists).
+// Hide LEGACY system-role daily_prep messages from earlier versions. The
+// current journal prep is a normal assistant message (renders with proper
+// bubble styling). Old system-role rows lurking in existing conversations
+// would render as a flat unstyled block — filter them.
 const hideMessage = computed(() =>
   props.message.role === "system" && metadata.value.kind === "daily_prep"
 );

frontend/src/views/JournalView.vue

@@ -13,7 +13,6 @@ import {
   triggerJournalPrep,
   listEvents,
   type EventEntry,
-  type JournalMessage,
 } from '@/api/client'
 
 interface WeatherDay {
@@ -53,21 +52,8 @@ const days = ref<string[]>([])
 const todayDate = ref<string | null>(null)
 const selectedDay = ref<string | null>(null)
 const dayConvId = ref<number | null>(null)
-const dayMessages = ref<JournalMessage[]>([])
 const isToday = computed(() => selectedDay.value !== null && selectedDay.value === todayDate.value)
 
-// ── Daily prep card ──────────────────────────────────────────────────────────
-const prepMessage = computed<JournalMessage | null>(() => {
-  return dayMessages.value.find(
-    (m) => m.role === 'system' && (m.metadata as { kind?: string } | null)?.kind === 'daily_prep',
-  ) ?? null
-})
-const prepSections = computed<Record<string, unknown>>(() => {
-  const meta = prepMessage.value?.metadata as { sections?: Record<string, unknown> } | null
-  return meta?.sections ?? {}
-})
-function asArray(v: unknown): unknown[] { return Array.isArray(v) ? v : [] }
-
 // ── Weather panel ────────────────────────────────────────────────────────────
 const weatherData = ref<WeatherData[]>([])
 const selectedWeatherIdx = ref(0)
@@ -153,7 +139,6 @@ async function loadEvents() {
 // ── Day load + switch ────────────────────────────────────────────────────────
 async function loadDay(iso: string) {
   const payload = iso === todayDate.value ? await getJournalToday() : await getJournalDay(iso)
-  dayMessages.value = payload.messages
   if (payload.conversation) {
     dayConvId.value = payload.conversation.id
     await chatStore.fetchConversation(payload.conversation.id)
@@ -167,7 +152,6 @@ async function loadAll() {
     const today = await getJournalToday()
     todayDate.value = today.day_date
     selectedDay.value = today.day_date
-    dayMessages.value = today.messages
     if (today.conversation) {
       dayConvId.value = today.conversation.id
       await chatStore.fetchConversation(today.conversation.id)
@@ -259,55 +243,8 @@ onMounted(async () => {
         </div>
       </header>
 
-      <!-- Center: prep card + chat -->
+      <!-- Center: chat (prep is the first assistant message inside) -->
       <div class="journal-center">
-        <article v-if="prepMessage" class="daily-prep">
-          <header><h2>Today</h2></header>
-
-          <section v-if="asArray(prepSections.tasks).length" class="prep-section">
-            <h3>Tasks</h3>
-            <ul>
-              <li v-for="t in (asArray(prepSections.tasks) as { id: number; title: string; due_date: string | null }[])" :key="t.id">
-                {{ t.title }}<span v-if="t.due_date"> · due {{ t.due_date }}</span>
-              </li>
-            </ul>
-          </section>
-
-          <section v-if="asArray(prepSections.events).length" class="prep-section">
-            <h3>Calendar</h3>
-            <ul>
-              <li v-for="(e, i) in (asArray(prepSections.events) as { id: number; title: string; start_dt: string }[])" :key="i">
-                {{ e.title }} — {{ e.start_dt }}
-              </li>
-            </ul>
-          </section>
-
-          <section v-if="asArray(prepSections.projects).length" class="prep-section">
-            <h3>Active projects</h3>
-            <ul>
-              <li v-for="p in (asArray(prepSections.projects) as { id: number; title: string }[])" :key="p.id">{{ p.title }}</li>
-            </ul>
-          </section>
-
-          <section v-if="asArray(prepSections.recent_moments).length" class="prep-section">
-            <h3>Recent moments</h3>
-            <ul>
-              <li v-for="m in (asArray(prepSections.recent_moments) as { id: number; content: string; day_date: string }[])" :key="m.id">
-                <em>{{ m.day_date }}</em> — {{ m.content }}
-              </li>
-            </ul>
-          </section>
-
-          <section v-if="asArray(prepSections.open_threads).length" class="prep-section">
-            <h3>Open threads</h3>
-            <ul>
-              <li v-for="m in (asArray(prepSections.open_threads) as { id: number; content: string; day_date: string }[])" :key="m.id">
-                <em>{{ m.day_date }}</em> — {{ m.content }}
-              </li>
-            </ul>
-          </section>
-        </article>
-
         <ChatPanel
           variant="full"
           briefingMode
@@ -445,31 +382,6 @@ onMounted(async () => {
 
 .journal-chat-panel { flex: 1; min-height: 0; }
 
-.daily-prep {
-  border: 1px solid var(--color-border);
-  border-radius: var(--radius-md);
-  padding: 1rem 1.25rem;
-  margin: 1rem 1rem 0.5rem;
-  background: var(--color-bg-card);
-  flex-shrink: 0;
-}
-.daily-prep > header h2 {
-  font-family: 'Fraunces', Georgia, serif;
-  font-size: 1.1rem;
-  margin: 0 0 0.5rem 0;
-}
-.prep-section { margin-top: 0.75rem; }
-.prep-section h3 {
-  font-size: 0.72rem;
-  text-transform: uppercase;
-  letter-spacing: 0.06em;
-  color: var(--color-text-muted);
-  margin: 0 0 0.25rem 0;
-  font-weight: 600;
-}
-.prep-section ul { margin: 0; padding-left: 1.1rem; font-size: 0.88rem; color: var(--color-text); }
-.prep-section li { margin-bottom: 0.15rem; }
-
 /* ── Right column ─────────────────────────────────────────────────────────── */
 .journal-right {
   grid-column: 2;