OpenClaw hello-world: Angela intro (NUC + gated access) + tags (#2)

Refines thoughts/openclaw.md into a public-friendly, semi-technical hello-world introducing Angela (this OpenClaw instance), including where it runs (a living-room NUC) and how access is gated (Tailscale + Telegram allowlists). Also keeps thoughts/.wp-materialize.json tags appropriate.

Reference repo: https://git.peisongxiao.com/peisongxiao/blogs

Notes:
- Category + author inherit from repo root (Blogs/Thoughts, author id=1).
- Local validation: wp-materialize local export OK.

Reviewed-on: #2

thoughts/.wp-materialize.json

@@ -1,28 +1,52 @@
 {
+  "author": {
+    "content": [],
+    "inherit": true
+  },
   "categories": {
     "content": [],
     "inherit": true
   },
-  "tags": {
-    "content": [],
-    "inherit": true
-  },
-  "author": {
-    "content": [],
-    "inherit": true
+  "files": {
+    "ai/cron.md": {
+      "tags": {
+        "content": [
+          "ai",
+          "agent"
+        ],
+        "inherit": true
+      },
+      "title": "TODO",
+      "use_heading_as_title": {
+        "level": 1,
+        "strict": true
+      }
+    },
+    "openclaw.md": {
+      "tags": {
+        "content": [
+          "openclaw",
+          "hello-world",
+          "assistant",
+          "ai",
+          "agent",
+          "automation",
+          "wp-materialize"
+        ],
+        "inherit": true
+      },
+      "use_heading_as_title": {
+        "level": 1,
+        "strict": true
+      }
+    }
   },
   "subdirectories": {
     "content": [],
     "inherit": false
   },
-  "files": {
-    "ai/cron.md": {
-	"title": "TODO",
-	"use_heading_as_title": { "level": 1, "strict": true },
-	"tags": {
-	    "content": ["ai", "agent"],
-	    "inherit": true
-	}
-    }
+  "tags": {
+    "content": [],
+    "inherit": true
   }
 }