fix: restore Chinese tags (my earlier removal was over-correction)

Schema explicitly allows 'mixed Chinese/English keywords' for discoverability.
Earlier commit 86f6d35 wrongly stripped Chinese tags based on a misremembered
review rule from PR #175/#176/#178 (which were actually about space→hyphen, not CN removal).

Chinese tags restored to match original feat commit, with space→hyphen applied
only to English multi-word tags. No lowercase changes.

Author: firstdata-dev

firstdata/sources/china/health/china-cdc.json

@@ -27,7 +27,13 @@
     "infectious-disease",
     "public-health",
     "vaccination",
-    "surveillance"
+    "surveillance",
+    "疾控中心",
+    "传染病",
+    "疫情监测",
+    "公共卫生",
+    "疫苗接种",
+    "慢性病"
   ],
   "data_content": {
     "en": [

firstdata/sources/china/resources/china-cnooc.json

@@ -27,7 +27,14 @@
     "lng",
     "deepwater",
     "marine-energy",
-    "state-owned-enterprise"
+    "state-owned-enterprise",
+    "中国海油",
+    "中海油",
+    "海上石油",
+    "天然气",
+    "液化天然气",
+    "深水",
+    "央企"
   ],
   "data_content": {
     "en": [

firstdata/sources/china/resources/china-cnpc.json

@@ -29,7 +29,13 @@
     "crude-oil",
     "natural-gas",
     "energy",
-    "state-owned-enterprise"
+    "state-owned-enterprise",
+    "中国石油",
+    "中石油",
+    "原油",
+    "天然气",
+    "油气",
+    "央企"
   ],
   "data_content": {
     "en": [

firstdata/sources/china/resources/china-sinopec.json

@@ -27,7 +27,13 @@
     "refining",
     "chemical",
     "energy",
-    "state-owned-enterprise"
+    "state-owned-enterprise",
+    "中国石化",
+    "中石化",
+    "石油化工",
+    "炼化",
+    "化工",
+    "央企"
   ],
   "data_content": {
     "en": [