feat: Phase 6 export — writes Grav entry folders from Immich originals

Implements GET /export summary view and POST /export/run which downloads
originals from Immich, writes entry.md with YAML frontmatter, and sets
group status to exported. Includes POST /export/overwrite for single-group
re-export. All 42 tests pass.

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

services/travel-memories/app/templates/phase6.html

@@ -0,0 +1,108 @@
+{% extends "base.html" %}
+{% block content %}
+<div class="p-6 max-w-3xl mx-auto" x-data="exportApp('{{ album_id }}')">
+  <h1 class="text-2xl font-bold mb-4">Export</h1>
+  <div class="stats shadow mb-6">
+    <div class="stat"><div class="stat-title">Ready to export</div>
+      <div class="stat-value text-primary">{{ to_export | length }}</div></div>
+    <div class="stat"><div class="stat-title">Skipped</div>
+      <div class="stat-value opacity-40">{{ skipped | length }}</div></div>
+  </div>
+
+  <div class="space-y-2 mb-6">
+    {% for group in to_export %}
+    <div class="export-item card card-compact bg-base-100 shadow">
+      <div class="card-body">
+        <p class="font-semibold">{{ group.title }}</p>
+        <p class="text-xs opacity-60">{{ group.date }} · {{ group.entry_type }} · {{ group.photo_ids | length }} photos</p>
+      </div>
+    </div>
+    {% endfor %}
+  </div>
+
+  <button id="export-btn" class="btn btn-primary" @click="runExport()">
+    Export {{ to_export | length }} entries
+  </button>
+
+  <!-- Overwrite confirmation modal -->
+  <dialog id="overwrite-modal" class="modal">
+    <div class="modal-box">
+      <h3 class="font-bold">Destination exists</h3>
+      <p x-text="overwriteMsg" class="py-2 text-sm"></p>
+      <div class="modal-action">
+        <button class="btn btn-warning btn-sm" @click="confirmOverwrite()">Overwrite</button>
+        <button class="btn btn-ghost btn-sm" @click="skipOverwrite()">Skip this entry</button>
+      </div>
+    </div>
+  </dialog>
+
+  <!-- Results -->
+  <div x-show="results.length > 0" class="mt-6 space-y-1">
+    <template x-for="r in results" :key="r.group_id">
+      <div class="text-sm" :class="r.needs_overwrite ? 'text-warning' : 'text-success'">
+        <span x-text="r.needs_overwrite ? '⚠ ' + r.title + ' — exists' : '✓ ' + r.title"></span>
+        <template x-if="r.failed_photos && r.failed_photos.length">
+          <span class="text-error ml-2" x-text="`(${r.failed_photos.length} photo(s) failed)`"></span>
+        </template>
+      </div>
+    </template>
+  </div>
+
+  <details class="mt-6">
+    <summary class="cursor-pointer text-sm opacity-60 skipped-list">
+      Skipped ({{ skipped | length }}) — not exported
+    </summary>
+    <ul class="mt-2 space-y-1 text-sm opacity-60">
+      {% for g in skipped %}<li>{{ g.title or g.date }}</li>{% endfor %}
+    </ul>
+  </details>
+</div>
+{% endblock %}
+
+{% block extra_scripts %}
+<script>
+function exportApp(albumId) {
+  return {
+    results: [],
+    pendingOverwrites: [],
+    currentOverwrite: null,
+    overwriteMsg: '',
+    confirmedIds: [],
+
+    async runExport(extraOverwrites = []) {
+      const res = await fetch('/export/run', {
+        method: 'POST', headers: {'Content-Type':'application/json'},
+        body: JSON.stringify({album_id: albumId, overwrite_ids: [...this.confirmedIds, ...extraOverwrites]}),
+      });
+      const data = await res.json();
+      const needsOverwrite = data.results.filter(r => r.needs_overwrite);
+      const done = data.results.filter(r => !r.needs_overwrite);
+      this.results.push(...done);
+      if (needsOverwrite.length > 0) {
+        this.pendingOverwrites = needsOverwrite;
+        this.showNextOverwrite();
+      }
+    },
+
+    showNextOverwrite() {
+      if (this.pendingOverwrites.length === 0) return;
+      this.currentOverwrite = this.pendingOverwrites.shift();
+      this.overwriteMsg = `"${this.currentOverwrite.title}" already exists at ${this.currentOverwrite.dest}`;
+      document.getElementById('overwrite-modal').showModal();
+    },
+
+    confirmOverwrite() {
+      document.getElementById('overwrite-modal').close();
+      this.confirmedIds.push(this.currentOverwrite.group_id);
+      this.runExport();
+    },
+
+    skipOverwrite() {
+      document.getElementById('overwrite-modal').close();
+      this.results.push({...this.currentOverwrite, skipped: true});
+      this.showNextOverwrite();
+    },
+  };
+}
+</script>
+{% endblock %}