feat: add SharePanel component for social sharing with QR code support

- Implemented SharePanel component in `SharePanel.astro` for sharing content on social media platforms.
- Integrated QR code generation for WeChat sharing using the `qrcode` library.
- Added localization support for English and Chinese languages.
- Created utility functions in `seo.ts` for building article summaries and FAQs.
- Introduced API routes for serving IndexNow key and generating full LLM catalog and summaries.
- Enhanced SEO capabilities with structured data for articles and pages.

backend/migration/src/lib.rs

@@ -44,6 +44,7 @@ mod m20260401_000033_add_taxonomy_metadata_and_media_assets;
 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;
 pub struct Migrator;
 
 #[async_trait::async_trait]
@@ -92,6 +93,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20260401_000034_add_source_markdown_to_posts::Migration),
             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),
             // inject-above (do not remove this comment)
         ]
     }

backend/migration/src/m20260402_000037_add_wechat_share_qr_setting_to_site_settings.rs

@@ -0,0 +1,52 @@
+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", "seo_wechat_share_qr_enabled")
+            .await?
+        {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table.clone())
+                        .add_column(
+                            ColumnDef::new(Alias::new("seo_wechat_share_qr_enabled"))
+                                .boolean()
+                                .null()
+                                .default(false),
+                        )
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        Ok(())
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        let table = Alias::new("site_settings");
+
+        if manager
+            .has_column("site_settings", "seo_wechat_share_qr_enabled")
+            .await?
+        {
+            manager
+                .alter_table(
+                    Table::alter()
+                        .table(table)
+                        .drop_column(Alias::new("seo_wechat_share_qr_enabled"))
+                        .to_owned(),
+                )
+                .await?;
+        }
+
+        Ok(())
+    }
+}