feat(03-05): add GPT4All, text-gen-webui, TensorRT-LLM, Triton, Jan AI provider YAMLs

- 5 more Tier 8 self-hosted runtime definitions (keyword-only)
- Completes 10 Tier 8 providers, satisfying PROV-08
- Dual-located in providers/ and pkg/providers/definitions/

providers/gpt4all.yaml

@@ -0,0 +1,16 @@
+format_version: 1
+name: gpt4all
+display_name: GPT4All
+tier: 8
+last_verified: "2026-04-05"
+keywords:
+  - "gpt4all"
+  - "nomic-ai"
+  - "GPT4ALL_API_KEY"
+  - "gpt4all.io"
+verify:
+  method: GET
+  url: ""
+  headers: {}
+  valid_status: []
+  invalid_status: []