feat: update tag and timeline share panel copy for clarity and conciseness

style: enhance global CSS for better responsiveness of terminal chips and navigation pills

test: remove inline subscription test and add maintenance mode access code test

feat: implement media library picker dialog for selecting images from the media library

feat: add media URL controls for uploading and managing media assets

feat: add migration for music_enabled and maintenance_mode settings in site settings

feat: implement maintenance mode functionality with access control

feat: create maintenance page with access code input and error handling

chore: add TypeScript declaration for QR code module

backend/migration/src/lib.rs

@@ -45,6 +45,8 @@ mod m20260401_000034_add_source_markdown_to_posts;
 mod m20260401_000035_add_human_verification_modes_to_site_settings;
 mod m20260402_000036_create_worker_jobs;
 mod m20260402_000037_add_wechat_share_qr_setting_to_site_settings;
+mod m20260402_000038_add_music_enabled_to_site_settings;
+mod m20260402_000039_add_maintenance_mode_to_site_settings;
 pub struct Migrator;
 
 #[async_trait::async_trait]
@@ -94,6 +96,8 @@ impl MigratorTrait for Migrator {
             Box::new(m20260401_000035_add_human_verification_modes_to_site_settings::Migration),
             Box::new(m20260402_000036_create_worker_jobs::Migration),
             Box::new(m20260402_000037_add_wechat_share_qr_setting_to_site_settings::Migration),
+            Box::new(m20260402_000038_add_music_enabled_to_site_settings::Migration),
+            Box::new(m20260402_000039_add_maintenance_mode_to_site_settings::Migration),
             // inject-above (do not remove this comment)
         ]
     }

backend/migration/src/m20260402_000038_add_music_enabled_to_site_settings.rs

@@ -0,0 +1,46 @@
+use sea_orm_migration::prelude::*;
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let table = Alias::new("site_settings");
+
+        if !manager.has_column("site_settings", "music_enabled").await? {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table.clone())
+                        .add_column(
+                            ColumnDef::new(Alias::new("music_enabled"))
+                                .boolean()
+                                .null()
+                                .default(true),
+                        )
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        Ok(())
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let table = Alias::new("site_settings");
+
+        if manager.has_column("site_settings", "music_enabled").await? {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table)
+                        .drop_column(Alias::new("music_enabled"))
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        Ok(())
+    }
+}

backend/migration/src/m20260402_000039_add_maintenance_mode_to_site_settings.rs

@@ -0,0 +1,84 @@
+use sea_orm_migration::prelude::*;
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let table = Alias::new("site_settings");
+
+        if !manager
+            .has_column("site_settings", "maintenance_mode_enabled")
+            .await?
+        {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table.clone())
+                        .add_column(
+                            ColumnDef::new(Alias::new("maintenance_mode_enabled"))
+                                .boolean()
+                                .null()
+                                .default(false),
+                        )
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        if !manager
+            .has_column("site_settings", "maintenance_access_code")
+            .await?
+        {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table)
+                        .add_column(
+                            ColumnDef::new(Alias::new("maintenance_access_code"))
+                                .text()
+                                .null(),
+                        )
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        Ok(())
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let table = Alias::new("site_settings");
+
+        if manager
+            .has_column("site_settings", "maintenance_access_code")
+            .await?
+        {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table.clone())
+                        .drop_column(Alias::new("maintenance_access_code"))
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        if manager
+            .has_column("site_settings", "maintenance_mode_enabled")
+            .await?
+        {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table)
+                        .drop_column(Alias::new("maintenance_mode_enabled"))
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        Ok(())
+    }
+}