feat(cli): add interactive email import tool for EML, MBOX, and Thunderbird

- Implement `bichonctl` interactive CLI using `dialoguer`.
- Support recursive EML directory scanning with folder structure preservation.
- Support single MBOX file streaming import.
- Support Thunderbird profile import with automatic `.sbd` hierarchy detection.
- Add batch processing (Base64 encoding & batch API requests) for improved performance.

src/modules/cli/sender.rs

@@ -0,0 +1,54 @@
+use console::style;
+use reqwest::Client;
+
+use crate::modules::{cli::BichonCtlConfig, import::BatchEmlRequest};
+
+pub async fn send_batch_request(
+    client: &Client,
+    config: &BichonCtlConfig,
+    account_id: u64,
+    folder: &str,
+    emls: Vec<String>,
+) {
+    let url = format!("{}/api/v1/import", config.base_url);
+    let payload = BatchEmlRequest {
+        account_id,
+        mail_folder: folder.to_string(),
+        emls,
+    };
+
+    let count = payload.emls.len();
+
+    match client
+        .post(&url)
+        .header("Authorization", format!("Bearer {}", config.api_token))
+        .json(&payload)
+        .send()
+        .await
+    {
+        Ok(res) if res.status().is_success() => {
+            println!(
+                "  {} Sent {} emails to [{}]",
+                style("✔").green(),
+                count,
+                folder
+            );
+        }
+        Ok(res) => {
+            eprintln!(
+                "  {} Failed to send to [{}]. Status: {}",
+                style("✘").red(),
+                folder,
+                res.status()
+            );
+        }
+        Err(e) => {
+            eprintln!(
+                "  {} Network error on [{}]: {}",
+                style("✘").red(),
+                folder,
+                e
+            );
+        }
+    }
+}