fix: enum 写入 PG 用 value 而非 name

Source/SourceKind、UserRole、SubscriptionMatch 三个 enum 改用 values_callable
保证 PG 看到 'rss' / 'owner' / 'any' 等小写 value,而非 'RSS' 大写 name。
seed_sources 同步改为显式字符串。

backend/app/scripts/seed_sources.py

@@ -18,13 +18,14 @@ from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.exc import IntegrityError
 
 from app.database import AsyncSessionLocal
-from app.models.source import Source, SourceKind
+from app.models.source import Source
 
+# 用字符串避免 SQLAlchemy 把 enum 写成 name(大写)而非 value(小写)
 SEEDS = [
     {
         "name": "Reuters World",
         "slug": "reuters-world",
-        "kind": SourceKind.RSS,
+        "kind": "rss",
         "url": "https://feeds.reuters.com/Reuters/worldNews",
         "region": "global",
         "language_src": "en",
@@ -36,7 +37,7 @@ SEEDS = [
     {
         "name": "BBC World",
         "slug": "bbc-world",
-        "kind": SourceKind.RSS,
+        "kind": "rss",
         "url": "https://feeds.bbci.co.uk/news/world/rss.xml",
         "region": "global",
         "language_src": "en",
@@ -48,7 +49,7 @@ SEEDS = [
     {
         "name": "Al Jazeera",
         "slug": "aljazeera",
-        "kind": SourceKind.RSS,
+        "kind": "rss",
         "url": "https://www.aljazeera.com/xml/rss/all.xml",
         "region": "mena",
         "language_src": "en",
@@ -60,7 +61,7 @@ SEEDS = [
     {
         "name": "NHK World",
         "slug": "nhk-world",
-        "kind": SourceKind.RSS,
+        "kind": "rss",
         "url": "https://www3.nhk.or.jp/rss/news/cat0.xml",
         "region": "asia",
         "language_src": "en",
@@ -72,7 +73,7 @@ SEEDS = [
     {
         "name": "DW (Deutsche Welle)",
         "slug": "dw",
-        "kind": SourceKind.RSS,
+        "kind": "rss",
         "url": "https://rss.dw.com/xml/rss-en-all",
         "region": "eu",
         "language_src": "en",