feat(cloud): add update single tag endpoint for Pro databases (#489)

Adds the ability to update a single tag value without replacing all tags:
- Add UpdateTag CLI command to CloudDatabaseCommands
- Add update_tag handler function in database_impl
- Add CLI test for update-tag help

Closes #471

Author: joshrotenberg

crates/redisctl/src/cli/cloud.rs

@@ -1329,6 +1329,18 @@ pub enum CloudDatabaseCommands {
         data: String,
     },
 
+    /// Update a single tag value
+    UpdateTag {
+        /// Database ID (format: subscription_id:database_id)
+        id: String,
+        /// Tag key
+        #[arg(long)]
+        key: String,
+        /// Tag value
+        #[arg(long)]
+        value: String,
+    },
+
     /// Delete a tag from database
     DeleteTag {
         /// Database ID (format: subscription_id:database_id)

crates/redisctl/src/commands/cloud/database.rs

@@ -205,6 +205,18 @@ pub async fn handle_database_command(
             )
             .await
         }
+        CloudDatabaseCommands::UpdateTag { id, key, value } => {
+            super::database_impl::update_tag(
+                conn_mgr,
+                profile_name,
+                id,
+                key,
+                value,
+                output_format,
+                query,
+            )
+            .await
+        }
         CloudDatabaseCommands::DeleteTag { id, key } => {
             super::database_impl::delete_tag(conn_mgr, profile_name, id, key, output_format, query)
                 .await

crates/redisctl/src/commands/cloud/database_impl.rs

@@ -680,6 +680,50 @@ pub async fn update_tags(
     Ok(())
 }
 
+/// Update a single tag value
+pub async fn update_tag(
+    conn_mgr: &ConnectionManager,
+    profile_name: Option<&str>,
+    id: &str,
+    key: &str,
+    value: &str,
+    output_format: OutputFormat,
+    query: Option<&str>,
+) -> CliResult<()> {
+    let (subscription_id, database_id) = parse_database_id(id)?;
+    let client = conn_mgr.create_cloud_client(profile_name).await?;
+
+    let request = json!({
+        "value": value
+    });
+
+    let response = client
+        .put_raw(
+            &format!(
+                "/subscriptions/{}/databases/{}/tags/{}",
+                subscription_id, database_id, key
+            ),
+            request,
+        )
+        .await
+        .context("Failed to update tag")?;
+
+    let result = if let Some(q) = query {
+        apply_jmespath(&response, q)?
+    } else {
+        response
+    };
+
+    match output_format {
+        OutputFormat::Table => {
+            println!("Tag '{}' updated successfully", key);
+        }
+        _ => print_json_or_yaml(result, output_format)?,
+    }
+
+    Ok(())
+}
+
 /// Delete a tag from database
 pub async fn delete_tag(
     conn_mgr: &ConnectionManager,

crates/redisctl/tests/cli_basic_tests.rs

@@ -2768,3 +2768,17 @@ fn test_enterprise_cluster_maintenance_mode_disable_help() {
         .success()
         .stdout(predicate::str::contains("maintenance"));
 }
+
+#[test]
+fn test_cloud_database_update_tag_help() {
+    redisctl()
+        .arg("cloud")
+        .arg("database")
+        .arg("update-tag")
+        .arg("--help")
+        .assert()
+        .success()
+        .stdout(predicate::str::contains("Update a single tag value"))
+        .stdout(predicate::str::contains("--key"))
+        .stdout(predicate::str::contains("--value"));
+}