feat(hooks): track model-skill-injector in workspace repo

hooks/model-skill-injector/HOOK.md

@@ -0,0 +1,39 @@
+---
+name: model-skill-injector
+description: "Injects model-specific best-practice context into bootstrap depending on the active LLM (Anthropic vs OpenAI)"
+metadata:
+  {
+    "openclaw": {
+      "emoji": "🧠",
+      "events": ["agent:bootstrap"],
+      "requires": { "config": ["workspace.dir"] }
+    }
+  }
+---
+
+# model-skill-injector
+
+Fires on `agent:bootstrap` and appends a model-family-specific best-practices
+hint file to the bootstrap context, so the agent always knows which tool-design
+rules apply for the currently active model — without bloating the base system
+prompt.
+
+## What it does
+
+1. Reads the active model string from the event config (`agents.defaults.model.primary`).
+2. Detects the model family by model name only:
+   - **Anthropic** — any model containing `claude`
+   - **OpenAI** — any model containing `gpt`
+3. Injects the corresponding hint file from the workspace `skills/llm-tool-best-practices/` folder as a virtual bootstrap file named `MODEL_HINTS.md`.
+4. If the model is unknown / not matched, injects a neutral fallback noting both families.
+
+## Files
+
+- Anthropic hints: `skills/llm-tool-best-practices/hints/anthropic.md`
+- OpenAI hints:    `skills/llm-tool-best-practices/hints/openai.md`
+- Fallback:        `skills/llm-tool-best-practices/hints/generic.md`
+
+## Notes
+
+- Runs read-only; never writes files.
+- Only injects the targeted section — does not load the full best-practices doc each turn.