feat: support announcement image upload

# Conflicts:
#	database.py
#	db/migrations.py
#	routes/admin_api/core.py
#	static/admin/.vite/manifest.json
#	static/admin/assets/AnnouncementsPage-Btl9JP7M.js
#	static/admin/assets/EmailPage-CwqlBGU2.js
#	static/admin/assets/FeedbacksPage-B_qDNL3q.js
#	static/admin/assets/LogsPage-DzdymdrQ.js
#	static/admin/assets/ReportPage-Bp26gOA-.js
#	static/admin/assets/SettingsPage-__r25pN8.js
#	static/admin/assets/SystemPage-C1OfxrU-.js
#	static/admin/assets/UsersPage-DhnABKcY.js
#	static/admin/assets/email-By53DCWv.js
#	static/admin/assets/email-ByiJ74rd.js
#	static/admin/assets/email-DkWacopQ.js
#	static/admin/assets/index-D5wU2pVd.js
#	static/admin/assets/tasks-1acmkoIX.js
#	static/admin/assets/update-DdQLVpC3.js
#	static/admin/assets/users-B1w166uc.js
#	static/admin/assets/users-CPJP5r-B.js
#	static/admin/assets/users-CnIyvFWm.js
#	static/admin/index.html
#	static/app/.vite/manifest.json
#	static/app/assets/AccountsPage-C48gJL8c.js
#	static/app/assets/AccountsPage-D387XNsv.js
#	static/app/assets/AccountsPage-DBJCAsJz.js
#	static/app/assets/LoginPage-BgK_Vl6X.js
#	static/app/assets/RegisterPage-CwADxWfe.js
#	static/app/assets/ResetPasswordPage-CVfZX_5z.js
#	static/app/assets/SchedulesPage-CWuZpJ5h.js
#	static/app/assets/SchedulesPage-Dw-mXbG5.js
#	static/app/assets/SchedulesPage-DwzGOBuc.js
#	static/app/assets/ScreenshotsPage-C6vX2U3V.js
#	static/app/assets/ScreenshotsPage-CreOSjVc.js
#	static/app/assets/ScreenshotsPage-DuTeRzLR.js
#	static/app/assets/VerifyResultPage-BzGlCgtE.js
#	static/app/assets/VerifyResultPage-CN_nr4V6.js
#	static/app/assets/VerifyResultPage-CNbQc83z.js
#	static/app/assets/accounts-BFaVMUve.js
#	static/app/assets/accounts-BYq3lLev.js
#	static/app/assets/accounts-Bc9j2moH.js
#	static/app/assets/auth-Dk_ApO4B.js
#	static/app/assets/index-BIng7uZJ.css
#	static/app/assets/index-CDxVo_1Z.js
#	static/app/index.html

db/migrations.py

@@ -81,6 +81,9 @@ def migrate_database(conn, target_version: int) -> None:
     if current_version < 15:
         _migrate_to_v15(conn)
         current_version = 15
+    if current_version < 16:
+        _migrate_to_v16(conn)
+        current_version = 16
 
     if current_version != int(target_version):
         set_current_version(conn, int(target_version))
@@ -672,3 +675,15 @@ def _migrate_to_v15(conn):
 
     if changed:
         conn.commit()
+
+
+def _migrate_to_v16(conn):
+    """迁移到版本16 - 公告支持图片字段"""
+    cursor = conn.cursor()
+    cursor.execute("PRAGMA table_info(announcements)")
+    columns = [col[1] for col in cursor.fetchall()]
+
+    if "image_url" not in columns:
+        cursor.execute("ALTER TABLE announcements ADD COLUMN image_url TEXT")
+        conn.commit()
+        print("  ✓ 添加 announcements.image_url 字段")