feat(skills): integrate NVIDIA/skills as a trusted skills hub tap

NVIDIA/skills is now a default trusted tap in the Hermes Skills Hub —
discoverable, browsable, searchable, and auto-updating through the same
pipeline that already serves OpenAI, Anthropic, and HuggingFace skills.

Rebased onto current main.

tools/skills_guard.py

@@ -36,7 +36,16 @@ from typing import List, Tuple
 # Hardcoded trust configuration
 # ---------------------------------------------------------------------------
 
-TRUSTED_REPOS = {"openai/skills", "anthropics/skills", "huggingface/skills"}
+TRUSTED_REPOS = {
+    "openai/skills",
+    "anthropics/skills",
+    "huggingface/skills",
+    # NVIDIA-verified skills: each entry ships a signed `skill.oms.sig`
+    # and a governance `skill-card.md` (sync pipeline drops anything
+    # missing the signature or card). Catalog details:
+    # https://github.com/NVIDIA/skills
+    "NVIDIA/skills",
+}
 
 INSTALL_POLICY = {
     #                  safe      caution    dangerous

tools/skills_hub.py

@@ -401,6 +401,14 @@ class GitHubSource(SkillSource):
         {"repo": "openai/skills", "path": "skills/.system/"},
         {"repo": "anthropics/skills", "path": "skills/"},
         {"repo": "huggingface/skills", "path": "skills/"},
+        # NVIDIA/skills: NVIDIA-verified skills for CUDA-X, AIQ, cuOpt,
+        # cuPyNumeric, DeepStream, NeMo, NemoClaw, etc. Each skill ships
+        # alongside a signed `skill.oms.sig`, an OMS-signed `skill-card.md`
+        # (governance card), and an `evals/` directory — synced daily from
+        # the NVIDIA product repos. Treated as `trusted` (see
+        # `tools/skills_guard.py::TRUSTED_REPOS`). Sample layout:
+        # https://github.com/NVIDIA/skills/tree/main/skills
+        {"repo": "NVIDIA/skills", "path": "skills/"},
         {"repo": "garrytan/gstack", "path": ""},
     ]