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/announcements.py

@@ -6,10 +6,12 @@ import db_pool
 from db.utils import get_cst_now_str
 
 
-def create_announcement(title, content, is_active=True):
+def create_announcement(title, content, image_url=None, is_active=True):
     """创建公告（默认启用；启用时会自动停用其他公告）"""
     title = (title or "").strip()
     content = (content or "").strip()
+    image_url = (image_url or "").strip()
+    image_url = image_url or None
     if not title or not content:
         return None
 
@@ -22,10 +24,10 @@ def create_announcement(title, content, is_active=True):
 
         cursor.execute(
             """
-            INSERT INTO announcements (title, content, is_active, created_at, updated_at)
-            VALUES (?, ?, ?, ?, ?)
+            INSERT INTO announcements (title, content, image_url, is_active, created_at, updated_at)
+            VALUES (?, ?, ?, ?, ?, ?)
             """,
-            (title, content, 1 if is_active else 0, cst_time, cst_time),
+            (title, content, image_url, 1 if is_active else 0, cst_time, cst_time),
         )
         conn.commit()
         return cursor.lastrowid
@@ -129,4 +131,3 @@ def dismiss_announcement_for_user(user_id, announcement_id):
         )
         conn.commit()
         return cursor.rowcount >= 0
-