sources: add 11 stock source adapters, expand catalog from 5 to 16 providers

6 API-based adapters: Pixabay Video, Coverr, NARA (U.S. National Archives),
Library of Congress, Pond5 Public Domain, Videvo. 5 scraper-based adapters
for sites without APIs: ESA, NOAA, Mixkit, Dareful, JAXA. All follow the
StockSource protocol and are auto-discovered — no tool code changes needed.

Updated scene-director, asset-director, and idea-director skills with
source routing guidance so agents know which provider to use for which
content type (e.g. nara for historical, noaa for ocean, esa for space).

Also includes: grok_video capability updates (native audio, 1-15s duration,
new aspect ratios), seedance_video tool (Seedance 2.0 via fal.ai),
ProductReveal Remotion composition registration.

skills/pipelines/documentary-montage/asset-director.md

@@ -8,7 +8,9 @@ clips that fill each slot. There are two paths:
 ### Standard Path: Corpus + CLIP Retrieval
 
 1. **Build the corpus** — fan the scene director's queries out across
-   Pexels / Archive.org / NASA / Wikimedia / Unsplash and download/embed the candidates.
+   all available stock sources (Pexels, Pixabay Video, Coverr, Mixkit,
+   Archive.org, NARA, Library of Congress, Pond5 PD, Videvo, NASA, ESA,
+   JAXA, NOAA, Dareful, Wikimedia, Unsplash) and download/embed the candidates.
 2. **Pick per slot** — run CLIP retrieval against the corpus with each
    slot description and choose one winner per slot.
 
@@ -91,7 +93,7 @@ direct_clip_search.execute({
         {"query": "satellite dish night sky",        "slot_id": "slot_03"},
         # ... one per slot
     ],
-    "sources": ["pexels", "archive_org", "wikimedia"],  # or omit for all available
+    "sources": ["pexels", "pixabay_video", "coverr", "mixkit", "archive_org"],  # or omit for all available
     "clips_per_query": 3,
     "filters": {
         "min_duration": 3,

skills/pipelines/documentary-montage/idea-director.md

@@ -156,7 +156,7 @@ Minimum fields the brief must carry:
   "tone": "elegiac",
   "duration_seconds": 90,
   "shape": "list",
-  "sources_allowed": ["pexels", "archive_org", "nasa"],
+  "sources_allowed": ["pexels", "pixabay_video", "coverr", "mixkit", "archive_org", "nara", "nasa"],
   "generated_clips_allowed": false,
   "narration": "none",
   "music_plan": {

skills/pipelines/documentary-montage/scene-director.md

@@ -145,8 +145,19 @@ based on what footage lives where:
 | Source | Strengths | Use when |
 |--------|-----------|----------|
 | `pexels` | Modern HD footage, clean shots, people, cities, nature | Default for modern/any era |
+| `pixabay_video` | Large community library, nature, people, technology, lifestyle | Gap-fills when Pexels misses; broad general footage |
+| `coverr` | Curated cinematic B-roll, nature, urban, abstract backgrounds | High-quality establishing shots, mood-setters, modern lifestyle |
+| `mixkit` | Curated HD/4K by Envato, nature, business, technology | Premium-feel B-roll, clean nature footage, no attribution needed |
 | `archive_org` | Prelinger home movies, mid-century educational film, 1940s-1980s texture | Vintage, wry, dreamlike, anything nostalgic |
+| `nara` | U.S. National Archives — WWII, Cold War, Apollo, civil rights, presidential | Historical American documentary, military, government, space race |
+| `loc` | Library of Congress — early cinema, newsreels, cultural recordings | Pre-1928 public domain footage, American history, folk traditions |
+| `pond5_pd` | Pond5 Public Domain — WWI/WWII, early cinema, historical speeches | Archival/vintage footage, Méliès, Edison, newsreels |
+| `videvo` | 90K+ free clips, nature, aerial, city, abstract, time-lapses | Large free library, complements Pexels with different contributors |
 | `nasa` | Earth-from-orbit, astronomy, flight, scale imagery | Reverent, anything about scale, space, planet, flight |
+| `esa` | European space missions, Hubble/Webb imagery, Earth observation | European space content, complements NASA for non-U.S. missions |
+| `jaxa` | Japanese space missions, Hayabusa, ISS Kibo module, H-IIA rockets | Asian space content, unique angle on space exploration |
+| `noaa` | Deep-sea ROV footage, marine life, coral reefs, weather, hurricanes | Ocean/underwater, unique deep-sea content, weather phenomena |
+| `dareful` | Boutique 4K nature — mountains, forests, waterfalls, time-lapses | High-quality nature B-roll, consistent visual style, aerial shots |
 | `wikimedia` | Commons photos and CC video, civic/documentary/public-event coverage | Public spaces, landmarks, protests, city texture, educational footage |
 | `unsplash` | Polished editorial stills, lifestyle, product-adjacent photography | Modern still-image support shots when motion footage is thin |