refactor: move skill to skills/inkreach-teable (from .agents/skills/)

git mv rename (history preserved); install.sh + README updated.
The skill is consumed via user-level install (~/.zcode/skills), so
in-repo .agents discovery was unnecessary.

skills/inkreach-teable/metadata.json

@@ -0,0 +1,16 @@
+{
+  "version": "0.1.0",
+  "organization": "inkreach",
+  "authors": ["inkreach"],
+  "tags": ["database", "teable", "no-code", "automation", "self-hosted"],
+  "abstract": "Operate a deployed inkreach-teable instance — configure tables, fields, records, views, and the self-built automation engine (8 triggers + 7 actions), plus development/deployment knowledge. Uses the inkreach-teable CLI which targets the project's own automation contract (not official teable CLI compatible).",
+  "engines": {
+    "inkreachTeableCli": ">=0.1"
+  },
+  "references": [
+    {
+      "title": "inkreach-teable",
+      "url": "https://github.com/yeuimu/teable"
+    }
+  ]
+}