feat: entry previews (#24)

* feat: entry previews (video, tweet, article, iframe, image, audio bar)

- Add PreviewPanel dispatch hub routing by entity_kind + artifact extension
- VideoPreview: HTML5 <video> for YouTube/Instagram/TikTok/Reddit/X posts
- TweetPreview: tweet card, thread, and X article renderer (ported from x-article-renderer)
- IframePreview: sandboxed iframe for SingleFile web pages and PDFs
- ImagePreview: image viewer with click-to-open-fullsize
- AudioBar: persistent fixed-bottom player (Spotify-style) that survives entry navigation
- Lift entryDetail to App.jsx, shared between PreviewPanel and ContextRail
- 3-column layout (workspace | 300px preview | 340px rail) when preview active
- Stale-guard fixes: seq incremented before early returns in all async effects
- handleRearchive: capture startSeq/entryUid at call time, guard every async resume
- TweetPreview: reset loading/error/tweets before early-return branches

* feat: entry previews — tweet/thread/article/video/audio/image/iframe/pdf

- PreviewModal: modal overlay with new-tab link (↗) and keyboard close
- PreviewPanel: routes by entity_kind + primary_media extension to the
  correct viewer (tweet/video/audio/pdf/html/image/fallback)
- TweetPreview: full X-style tweet, thread, and article renderer with
  local artifact map for archived media (CDN fallback)
- AudioBar: persistent fixed bottom player, triggered via ContextRail
  Play button; body.has-audio-bar pads content above it
- VideoPreview, IframePreview, ImagePreview: inline viewers
- PreviewPage: standalone /preview/:archiveId/:entryUid route
- ContextRail: Play/Preview buttons; isAudio/isPreviewable detection
- App.jsx: preview modal state, currentAudio state, preview route guard,
  has-audio-bar body class effect
- routes.rs: CSP updated (media-src self blob https; frame-ancestors self;
  Google Fonts + external images/scripts whitelisted)
- styles.css: preview modal, tweet-wrap scroll (min-height:0), audio bar
  body padding, newtab button, preview panel flex layout

* style: tighten article/tweet preview spacing

- aMeta padding: 14px → 10px
- article title marginBottom: 10px → 8px
- aAuthorRow marginBottom: 10px → 8px
- bH1 top margin: 20px → 16px
- bH2 top margin: 18px → 14px
- bHr margin: 20px → 14px
- .preview-tweet-wrap padding: 20px → 12px (already committed)

More content visible above the fold in both modal and standalone views.

* feat: tweet/article preview quality pass

HTML entities: decode &gt; &lt; &amp; etc. on sliced segments only
(entity offsets index the stored string; decoding before slicing shifts them)

Image lightbox: click any tweet/thread/article image to open full-screen
viewer; cmd+click follows <a> to open in new tab; arrow-key + ‹ › nav;
Escape closes; 1/N counter; ↗ open-in-new-tab link

Multi-image grid: 2 photos → side-by-side (180px rows); 3 → left spans
both rows; 4 → 2×2 (140px rows); single image unchanged

Empty media grid ghost: build photos/videoItems arrays first, render
.mediaGrid div only when at least one item resolved (advisory: never gate
on raw media.length when map items can all return null)

QT indicator: ↻ QT badge on tweet.is_quote_status === true entries

Modal shrinks for short content: height: 88vh → max-height: 88vh;
.preview-modal-body gets max-height: calc(88vh - 52px) so long threads
still scroll (advisory: don't rely on flex:1 once parent has no fixed height)

Video scrollbar leak: .preview-modal-body overflow: auto → hidden; each
child (tweet-wrap, video-wrap, iframe) manages its own scroll surface

Styled thin scrollbar on .preview-tweet-wrap (matches workspace rail)

ArticleRenderer: cover image and body images are lightbox-clickable;
opts thread through renderBlocksJSX → renderBlockJSX → renderAtomicJSX

* fix: move artifact fetch to api.js; stop Escape propagation from lightbox

- Export fetchEntryArtifacts(archiveId, entryUid, indices) from api.js
  using Promise.all + getJson (follows project convention: all /api calls
  go through api.js, never inline fetch in components)
- TweetPreview: import fetchEntryArtifacts, replace inline Promise.all
- MediaLightbox keydown handler: stopPropagation + preventDefault for
  Escape/ArrowLeft/ArrowRight so the parent PreviewModal window listener
  does not also fire and close the modal behind the lightbox

* fix: iframe/page preview height chain and toolbar UX

Problem: changing .preview-modal from height to max-height broke iframe
previews - <iframe style='flex:1'> needs a concrete ancestor height, which
max-height alone doesn't supply when content is shorter than the cap.

Fix - CSS:
  .preview-modal--full { height: 88vh } applied to non-tweet modals
  .preview-modal--full .preview-modal-body { max-height: none }
  .preview-iframe-toolbar span: remove text-transform/letter-spacing
    (was uppercasing the URL/title in shouty caps)

Fix - PreviewModal: className adds --full when entity_kind is not
  tweet/tweet_thread; tweet previews keep shrink-to-fit behavior.

Fix - PreviewPanel: pass title + original_url from summary to IframePreview
  for both HTML and PDF; wrappers use flex:1/minHeight:0 not height:100%.

Fix - IframePreview:
  - Accept title + originalUrl props; show originalUrl in toolbar (falls
    back to artifact src only when original_url absent); show title above
    URL when available
  - flex:1 + minHeight:0 instead of height:100% on the wrap div
  - Single unified layout for page + pdf (both just show the iframe)

* feat: expand t.co links; linkify bare URLs in tweet and article text

Frontend:
- resolveEntityBounds: try multiple candidate strings in order (u.url
  first, since that's the t.co short URL that appears in full_text)
- normalizeUrlAnn: multi-candidate search; href = expanded > url,
  display = display_url > expanded > url
- linkifyText(): regex linkifier for entity-less bare URLs; trims
  trailing punctuation [.,;:!?)] before linking; used in both
  renderTweetTextJSX and renderInlineJSX including their early-return
  paths (anns.length === 0) that previously bypassed linkification
- renderInlineJSX: fix mention href mention.name → screen_name;
  replace t.co segment text with url.display when entity covers it

Scraper (vendor/twitter/scrape_user_tweet_contents.py):
- extract_tweet_data: when note_tweet text is used, pull urls/mentions/
  hashtags/symbols from note_result.entity_set (correct indices for the
  note text); keep media from legacy.entities (no note media downloads)

* feat: server-side t.co resolver + frontend augmentation

Server (routes.rs):
  POST /api/util/resolve-tco — unauthenticated, accepts JSON array of
  https://t.co/<alphanumeric> URLs only (strict regex validation, no SSRF
  via input), capped at 50 per batch, 3 s timeout, redirect(Policy::none)
  so the server only ever touches t.co itself. HEAD first, GET fallback if
  HEAD returns no Location. Location sanitized to http/https only —
  javascript:/data:/etc. fall back to the original t.co.

api.js:
  resolveTcoUrls(urls) — project-convention wrapper for the new endpoint.
  Returns {} on failure (callers degrade gracefully to bare t.co links).

TweetPreview.jsx:
  After tweet data loads, per-tweet range-based coverage detection:
  builds covered [start,end) from existing entity fromIndex/toIndex or
  indices fallback, then finds regex matches whose span is NOT covered.
  Resolves unique uncovered t.co URLs via resolveTcoUrls(), synthesises
  one entity per occurrence (with exact fromIndex/toIndex so normalizeUrlAnn
  gets correct bounds even for duplicate t.co URLs in the same tweet).
  Augments entities.urls before setTweets() so all rendering paths
  see expanded URLs.

* feat: suppress rendered media attachment URLs from tweet text

renderTweetTextJSX now accepts skipSpans=[] as third param.
Skip-span boundaries are added to the pts split set so a trailing
media t.co inside a plain segment still gets isolated and suppressed—
not re-linked by linkifyText. Early return only when both anns and
skipSpans are empty.

TweetCard computes mediaSkipSpans after building photos/videoItems:
for each rawMedia item whose src resolved (photo src match; any video),
resolveEntityBounds(m, ft, m.url) gives the precise [s,e] span using
indices/fromIndex first, indexOf fallback—then the span is passed to
renderTweetTextJSX so the t.co attachment URL is silently dropped.

frontend/src/components/PreviewPanel.jsx

@@ -0,0 +1,153 @@
+import VideoPreview from './VideoPreview';
+import IframePreview from './IframePreview';
+import ImagePreview from './ImagePreview';
+import TweetPreview from './TweetPreview';
+
+const VIDEO_EXTS = new Set(['mp4', 'webm', 'mov', 'mkv', 'avi', 'm4v', 'ogv']);
+const AUDIO_EXTS = new Set(['mp3', 'ogg', 'm4a', 'opus', 'wav', 'flac', 'aac']);
+const IMAGE_EXTS = new Set(['jpg', 'jpeg', 'png', 'gif', 'webp', 'avif', 'svg', 'bmp']);
+
+export default function PreviewPanel({ archiveId, entry, detail }) {
+
+  if (!entry) {
+    return (
+      <div className="preview-panel preview-panel--empty">
+        <span style={{ color: 'var(--muted)', fontFamily: 'var(--sans)', fontSize: '0.9rem' }}>
+          Select an entry to preview
+        </span>
+      </div>
+    );
+  }
+
+  if (!detail) {
+    return (
+      <div className="preview-panel preview-panel--loading">
+        <span style={{ color: 'var(--muted)', fontFamily: 'var(--sans)', fontSize: '0.9rem' }}>
+          Loading…
+        </span>
+      </div>
+    );
+  }
+
+  const { summary, artifacts } = detail;
+  const entryUid = summary.entry_uid;
+  const entityKind = summary.entity_kind;
+
+  // 1. Tweet / tweet thread
+  if (entityKind === 'tweet' || entityKind === 'tweet_thread') {
+    return (
+      <div className="preview-tweet-wrap">
+        <TweetPreview
+          archiveId={archiveId}
+          entryUid={entryUid}
+          artifacts={artifacts}
+          entityKind={entityKind}
+        />
+      </div>
+    );
+  }
+
+  // 2. Find primary_media artifact
+  const primaryMediaIndex = artifacts.findIndex(a => a.artifact_role === 'primary_media');
+  if (primaryMediaIndex === -1) {
+    return (
+      <div className="preview-panel preview-panel--no-preview">
+        <span style={{ color: 'var(--muted)', fontFamily: 'var(--sans)', fontSize: '0.9rem' }}>
+          No preview available
+        </span>
+        {artifacts.length > 0 && (
+          <ul
+            style={{
+              marginTop: '12px',
+              paddingLeft: '20px',
+              fontSize: '0.8rem',
+              color: 'var(--muted-2)',
+              fontFamily: 'var(--sans)',
+            }}
+          >
+            {artifacts.map((a, i) => (
+              <li key={i}>{a.artifact_role}: {a.relpath}</li>
+            ))}
+          </ul>
+        )}
+      </div>
+    );
+  }
+
+  const primaryArtifact = artifacts[primaryMediaIndex];
+  const primaryMediaUrl = `/api/archives/${archiveId}/entries/${entryUid}/artifacts/${primaryMediaIndex}`;
+  const ext = primaryArtifact.relpath.split('.').pop().toLowerCase();
+
+  // 3. Video
+  if (VIDEO_EXTS.has(ext)) {
+    return (
+      <div className="preview-panel">
+        <VideoPreview src={primaryMediaUrl} />
+      </div>
+    );
+  }
+
+  // 4. Audio — inline player (AudioBar handles persistent playback via rail Play button)
+  if (AUDIO_EXTS.has(ext)) {
+    return (
+      <div className="preview-panel preview-panel--audio" style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', justifyContent: 'center', gap: '12px', padding: '24px', fontFamily: 'var(--sans)' }}>
+        <span style={{ fontSize: '2rem' }}>🎵</span>
+        <span style={{ color: 'var(--ink)', fontSize: '0.95rem', fontWeight: 600 }}>
+          {summary.title || entryUid}
+        </span>
+        <audio src={primaryMediaUrl} controls style={{ marginTop: '8px', width: '100%', maxWidth: '400px' }} />
+      </div>
+    );
+  }
+
+  // 5. PDF
+  if (ext === 'pdf') {
+    return (
+      <div className="preview-panel" style={{ flex: 1, minHeight: 0 }}>
+        <IframePreview src={primaryMediaUrl} type="pdf"
+          title={summary.title} originalUrl={summary.original_url} />
+      </div>
+    );
+  }
+
+  // 6. HTML page
+  if (ext === 'html' || ext === 'htm') {
+    return (
+      <div className="preview-panel" style={{ flex: 1, minHeight: 0 }}>
+        <IframePreview src={primaryMediaUrl} type="page"
+          title={summary.title} originalUrl={summary.original_url} />
+      </div>
+    );
+  }
+
+  // 7. Image
+  if (IMAGE_EXTS.has(ext)) {
+    return (
+      <div className="preview-panel" style={{ height: '100%' }}>
+        <ImagePreview src={primaryMediaUrl} alt={summary.title || 'Image'} />
+      </div>
+    );
+  }
+
+  // 8. Fallback
+  return (
+    <div className="preview-panel preview-panel--no-preview">
+      <span style={{ color: 'var(--muted)', fontFamily: 'var(--sans)', fontSize: '0.9rem' }}>
+        No preview available
+      </span>
+      <ul
+        style={{
+          marginTop: '12px',
+          paddingLeft: '20px',
+          fontSize: '0.8rem',
+          color: 'var(--muted-2)',
+          fontFamily: 'var(--sans)',
+        }}
+      >
+        {artifacts.map((a, i) => (
+          <li key={i}>{a.artifact_role}: {a.relpath}</li>
+        ))}
+      </ul>
+    </div>
+  );
+}