feat: initial itpp-docs setup with MkDocs Material

- mkdocs.yml with dark slate theme, nav for 12 ITPP projects
- build-docs.sh aggregates docs from all project repos
- .gitea/workflows/docs-publish.yml for nightly rebuild+deploy
- README and CHANGELOG for the itpp-docs repo itself
- docs-source/ populated from all 12 repos
- site/ ready for deployment to docs.itpropartner.com

docs-source/itpp-infrastructure/model-chain.md

@@ -0,0 +1,18 @@
+# AI Model Chain — IT Pro Partner
+
+**Updated:** July 24, 2026
+
+## Active Fallback Chain
+
+| Tier | Model | Provider | Notes |
+|---|---|---|---|
+| **Primary** | `claude-sonnet-5` | `admin-ai` | Conductor via LiteLLM ($3.33/day cap) |
+| **Fallback 1 (F1)** | `deepseek-v4-pro` | `deepseek` | Direct DeepSeek API |
+| **Fallback 2 (F2)** | `gpt-5.6-terra` | `admin-ai` | Demoted from Primary via LiteLLM ($3.33/day cap) |
+| **Fallback 3 (F3)** | `grok-4.5` (`grok-2-1212`) | `xai` | Direct xAI API |
+| **Fallback 4 (F4)** | `gemini-3.6-flash` | `google` | Direct Google API |
+
+## Admin-AI Virtual Key
+- **Key Hash**: `0237186aaff1ed90295c00d73103103900d4bd07252ec1806af8a4358e45d37a`
+- **Allowed Models**: `claude-sonnet-5`, `gpt-5.6-terra`, `deepseek-v4-pro`, `deepseek-v4-flash`, `glm-5.2`, `MiniMax-M3`, `qwen3.7-plus`
+- **Daily Budget Cap**: $3.33 / day