refactor(ingest): per-post handling into run stdout via a downloader outcome (#842)

Two corrections from operator review:
1. Reuse the existing 'Raw stdout' panel instead of a bespoke structured UI
   section — the native ingester now writes a per-post line into the run stdout
   (parity with gallery-dl's per-file stdout), so the per-post handling shows in
   the panel the operator already uses.
2. DRY: stop re-reading post['attributes'] inline in ingest_core. write_post_record
   now returns a PostRecordOutcome (path, post_type, title, body_chars) — mirroring
   the download_post -> MediaOutcome contract — and the downloader owns the read;
   ingest_core only formats the outcome into the log line.

Reverts the post_diagnostics metadata field + DownloadDetailModal 'Post capture'
section added earlier. Per-post line: 'post <id> [<post_type>] body: N chars' (+
' — EMPTY' when 0), so an empty body is self-explanatory by post_type.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/components/downloads/DownloadDetailModal.vue

@@ -28,54 +28,6 @@
           <div><span class="fc-dl-grid__label">Errors</span><span>{{ summary.errors ?? 0 }}</span></div>
         </div>
 
-        <template v-if="postDiag.length">
-          <h3 class="text-subtitle-2 mt-4">Post capture</h3>
-          <div class="fc-dl-grid">
-            <div><span class="fc-dl-grid__label">Posts</span><span>{{ postDiag.length }}</span></div>
-            <div><span class="fc-dl-grid__label">With body</span><span>{{ postWithBody }}</span></div>
-            <div><span class="fc-dl-grid__label">Empty body</span><span>{{ postEmpty.length }}</span></div>
-          </div>
-          <v-expansion-panels class="mt-2">
-            <v-expansion-panel v-if="postEmpty.length">
-              <v-expansion-panel-title>
-                <span>Empty-body posts ({{ postEmpty.length }})</span>
-              </v-expansion-panel-title>
-              <v-expansion-panel-text>
-                <table class="fc-dl-table">
-                  <thead><tr><th>Post</th><th>Type</th><th>Chars</th></tr></thead>
-                  <tbody>
-                    <tr v-for="p in postEmpty" :key="p.post_id" class="fc-dl-empty">
-                      <td>{{ p.title || `#${p.post_id}` }}</td>
-                      <td><code>{{ p.post_type || '—' }}</code></td>
-                      <td>{{ p.body_chars }}</td>
-                    </tr>
-                  </tbody>
-                </table>
-              </v-expansion-panel-text>
-            </v-expansion-panel>
-            <v-expansion-panel>
-              <v-expansion-panel-title>
-                <span>All posts ({{ postDiag.length }})</span>
-              </v-expansion-panel-title>
-              <v-expansion-panel-text>
-                <table class="fc-dl-table">
-                  <thead><tr><th>Post</th><th>Type</th><th>Chars</th></tr></thead>
-                  <tbody>
-                    <tr
-                      v-for="p in postDiag" :key="p.post_id"
-                      :class="{ 'fc-dl-empty': !p.body_chars }"
-                    >
-                      <td>{{ p.title || `#${p.post_id}` }}</td>
-                      <td><code>{{ p.post_type || '—' }}</code></td>
-                      <td>{{ p.body_chars }}</td>
-                    </tr>
-                  </tbody>
-                </table>
-              </v-expansion-panel-text>
-            </v-expansion-panel>
-          </v-expansion-panels>
-        </template>
-
         <template v-if="quarantinedPaths.length">
           <h3 class="text-subtitle-2 mt-4">Quarantined paths</h3>
           <ul class="fc-dl-quar">
@@ -163,31 +115,18 @@ const summary = computed(() => props.event?.metadata?.import_summary || {})
 const quarantinedPaths = computed(() => props.event?.metadata?.quarantined_paths || [])
 const errorsWarnings = computed(() => props.event?.metadata?.stderr_errors_warnings || '')
 
-// #842: per-post body-capture diagnostics — how each post was handled, with
-// post_type so an empty body is self-explanatory in the UI.
-const postDiag = computed(() => props.event?.metadata?.post_diagnostics || [])
-const postEmpty = computed(() => postDiag.value.filter((p) => !p.body_chars))
-const postWithBody = computed(() => postDiag.value.length - postEmpty.value.length)
-
 // One combined block for "research the issue elsewhere" — header line +
 // error + full stdout/stderr. Built lazily from the current event.
 const allDiagnostics = computed(() => {
   const e = props.event
   if (!e) return ''
   const md = e.metadata || {}
-  const emptyPosts = postEmpty.value
-    .map((p) => `  • ${p.title || '#' + p.post_id} [${p.post_type || '—'}] ${p.body_chars} chars`)
-    .join('\n')
   return [
     `event #${e.id} · ${e.platform || '—'} · ${e.artist_name || '—'}`,
     `status: ${e.status}`,
     `started: ${e.started_at}  finished: ${e.finished_at || '(running)'}`,
     e.error ? `\n--- error ---\n${e.error}` : '',
     errorsWarnings.value ? `\n--- errors & warnings ---\n${errorsWarnings.value}` : '',
-    postDiag.value.length
-      ? `\n--- post capture (${postWithBody.value}/${postDiag.value.length} with body) ---`
-      + (emptyPosts ? `\nempty-body posts:\n${emptyPosts}` : '')
-      : '',
     `\n--- stdout ---\n${md.stdout || '(empty)'}`,
     `\n--- stderr ---\n${md.stderr || '(empty)'}`,
   ].filter(Boolean).join('\n')
@@ -242,25 +181,6 @@ function onClose() {
   word-break: break-all;
 }
 .fc-dl-quar { padding-left: 1.5rem; font-size: 0.85rem; }
-.fc-dl-table {
-  width: 100%;
-  border-collapse: collapse;
-  font-size: 0.8rem;
-}
-.fc-dl-table th,
-.fc-dl-table td {
-  text-align: left;
-  padding: 0.2rem 0.5rem;
-  border-bottom: 1px solid rgb(var(--v-theme-on-surface-variant) / 0.14);
-}
-.fc-dl-table th:last-child,
-.fc-dl-table td:last-child {
-  text-align: right;
-  font-variant-numeric: tabular-nums;
-}
-.fc-dl-table .fc-dl-empty {
-  color: rgb(var(--v-theme-warning));
-}
 .fc-dl-blockhead {
   display: flex; align-items: center; justify-content: space-between;
   gap: 0.5rem;