catalog: repoint 3 urls after publisher domain moves (batch C)

Link-checked all 294 entry urls this run. Zero 404s. Three active entries
resolved 200 at a different root domain:

  blenderkit    www.blenderkit.com          -> www.blendkit.com
  nasa-3d       nasa3d.arc.nasa.gov         -> science.nasa.gov/3d-resources
  nasadem       lpdaac.usgs.gov/products/.. -> earthdata.nasa.gov catalog

blenderkit is a rebrand, not a hijack: the destination titles itself "Blender
Asset Library ... | Blendkit" and the entry body already documented the rename.
The other two are NASA and USGS site consolidations.

verified: is deliberately unchanged on all three. I fetched the landing pages
to confirm identity and status, but did not re-read the license text on any of
them, so this is a url correction and not a verification. Each entry carries a
note saying exactly that, so a later reader does not mistake the fresh url for
a fresh license check.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wc67NX9MM964uaVGn4bpZJ

Author: TMHSDigital

catalog/3d/blenderkit.md

@@ -1,7 +1,7 @@
 ---
 id: blenderkit
 name: Blendkit
-url: https://www.blenderkit.com
+url: https://www.blendkit.com
 category: 3d
 subcategories: [models, materials, hdri]
 license: varies
@@ -20,6 +20,7 @@ In-Blender (and now Godot/Maya/Rhino) asset library, formerly BlenderKit. Live s
 ## Notes
 
 - License hub: [blendkit.com/docs/licenses/](https://www.blendkit.com/docs/licenses/) (page title still "Lincenses")
+- Entry `url` moved to blendkit.com on 2026-09-22 after a link check; blenderkit.com still redirects there. Domain move only, no license re-check that day
 - Check the badge on the asset you click. Do not inherit RF vs CC0 from a neighboring thumbnail
 - "sell higher-level-derivative works" is their phrase for shipping a game. Republishing a kit is the banned path
 - Engine add-ons (Godot/Maya) have their own store ToS. This entry is the asset license page, not each add-on

catalog/environment/nasa-3d-resources.md

@@ -1,7 +1,7 @@
 ---
 id: nasa-3d-resources
 name: NASA 3D Resources
-url: https://nasa3d.arc.nasa.gov/
+url: https://science.nasa.gov/3d-resources/
 publisher: NASA
 category: environment
 subcategories: [models, planetary, public-domain]
@@ -24,6 +24,7 @@ US federal 3D models (spacecraft, planetary props). NASA media used in 3D models
 - Check each item for third-party copyright marks
 - No NASA insignia/logos as product branding; no false endorsement
 - Attribution example: `NASA 3D Resources / NASA`
+- Entry `url` moved to science.nasa.gov/3d-resources on 2026-09-22 after a link check; nasa3d.arc.nasa.gov redirects there. Domain move only, no license re-check that day
 
 ## Evidence
 

catalog/environment/nasadem.md

@@ -1,7 +1,7 @@
 ---
 id: nasadem
 name: NASADEM (LP DAAC)
-url: https://lpdaac.usgs.gov/products/nasadem_hgtv001/
+url: https://www.earthdata.nasa.gov/data/catalog/lpcloud-nasadem-hgt-001
 publisher: NASA
 category: environment
 subcategories: [heightmaps, dem]
@@ -23,6 +23,7 @@ status: active
 
 - Coverage roughly 60°N–56°S land. Citation strongly urged even though CC0.
 - Prefer over scraping Google/Bing elevation — see [`docs/high-risk.md`](../../docs/high-risk.md).
+- Entry `url` moved to the Earthdata catalog on 2026-09-22 after a link check; the LP DAAC product page redirects there. Domain move only, no license re-check that day.
 
 ## Evidence