chore(core): fix pre-existing clippy warnings (-D warnings gate)

Resolves pre-existing lint issues in imgsecret.rs, time.rs, totp.rs,
and crypto.rs that blocked the cargo clippy --workspace -D warnings
gate. No logic changes: loop-index → iterator, manual div_ceil →
.div_ceil(), manual range contains → .contains(), auto-deref cleanup.

Also fixes pre-existing warnings in relicario-cli (main.rs, session.rs,
device.rs, gitea.rs, helpers.rs, test helpers): dead_code suppression,
too_many_arguments, literal_with_empty_format_string, manual_char_cmp,
map_or → is_none_or, and repeat().take() → vec! in test helpers.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/relicario-cli/src/main.rs

@@ -540,7 +540,7 @@ fn cmd_init(image: PathBuf, output: PathBuf) -> Result<()> {
     };
     let carrier = fs::read(&image)
         .with_context(|| format!("failed to read carrier image {}", image.display()))?;
-    let stego = imgsecret::embed(&carrier, &*image_secret)?;
+    let stego = imgsecret::embed(&carrier, &image_secret)?;
     fs::write(&output, &stego)
         .with_context(|| format!("failed to write reference image {}", output.display()))?;
 
@@ -550,7 +550,7 @@ fn cmd_init(image: PathBuf, output: PathBuf) -> Result<()> {
     let params = KdfParams { argon2_m: 65536, argon2_t: 3, argon2_p: 4 };
 
     // Derive master key, then persist an empty Manifest + default VaultSettings.
-    let master_key = derive_master_key(passphrase.as_bytes(), &*image_secret, &salt, &params)?;
+    let master_key = derive_master_key(passphrase.as_bytes(), &image_secret, &salt, &params)?;
 
     fs::create_dir_all(&relicario_dir)?;
     fs::create_dir_all(root.join("items"))?;
@@ -645,6 +645,7 @@ fn cmd_add(kind: AddKind) -> Result<()> {
 //     (for attachment-cap settings + writing the encrypted blob alongside
 //     the item).
 
+#[allow(clippy::too_many_arguments)]
 fn build_login_item(
     title: Option<String>,
     username: Option<String>,
@@ -860,6 +861,7 @@ fn build_document_item(
     Ok(item)
 }
 
+#[allow(clippy::too_many_arguments)]
 fn build_totp_item(
     title: Option<String>,
     issuer: Option<String>,
@@ -924,7 +926,7 @@ fn prompt_optional(label: &str) -> Result<Option<String>> {
 
 fn parse_month_year(s: &str) -> Result<relicario_core::MonthYear> {
     // Accepts MM/YYYY or MM-YYYY or MM/YY.
-    let (m_str, y_str) = s.split_once(|c: char| c == '/' || c == '-')
+    let (m_str, y_str) = s.split_once(['/', '-'])
         .ok_or_else(|| anyhow::anyhow!("expected MM/YYYY"))?;
     let month: u8 = m_str.parse().context("invalid month")?;
     let year: u16 = if y_str.len() == 2 {
@@ -998,12 +1000,12 @@ fn cmd_get(query: String, show: bool, copy: bool) -> Result<()> {
             if let Some(u) = &l.url { println!("URL:      {u}"); }
             if let Some(t) = &l.totp {
                 if show {
-                    println!("TOTP:     {}", data_encoding::BASE32.encode(&*t.secret));
+                    println!("TOTP:     {}", data_encoding::BASE32.encode(&t.secret));
                 } else {
                     println!("TOTP:     ****  (use --show to reveal)");
                 }
             }
-            if let Some(p) = &l.password { Some(p.clone()) } else { None }
+            l.password.clone()
         }
         ItemCore::SecureNote(n) => {
             if show { println!("Body:\n{}", n.body.as_str()); }
@@ -1125,8 +1127,8 @@ fn cmd_list(
             Some(t) => e.r#type == t,
             None => true,
         })
-        .filter(|e| group_filter.as_ref().map_or(true, |g| e.group.as_deref() == Some(g.as_str())))
-        .filter(|e| tag_filter.as_ref().map_or(true, |t| e.tags.iter().any(|x| x == t)))
+        .filter(|e| group_filter.as_ref().is_none_or(|g| e.group.as_deref() == Some(g.as_str())))
+        .filter(|e| tag_filter.as_ref().is_none_or(|t| e.tags.iter().any(|x| x == t)))
         .collect();
     entries.sort_by(|a, b| a.title.to_lowercase().cmp(&b.title.to_lowercase()));
 
@@ -1135,7 +1137,7 @@ fn cmd_list(
         return Ok(());
     }
 
-    println!("{:<16}  {:<14}  {:<6}  {}", "ID", "TYPE", "FAV", "TITLE");
+    println!("{:<16}  {:<14}  {:<6}  TITLE", "ID", "TYPE", "FAV");
     for e in entries {
         let fav = if e.favorite { "  *" } else { "" };
         println!("{:<16}  {:<14}  {:<6}  {}", e.id.as_str(), format!("{:?}", e.r#type), fav, e.title);
@@ -1973,7 +1975,7 @@ fn cmd_attachments(query: String) -> Result<()> {
     let entry = resolve_query(&manifest, &query)?;
     let item = vault.load_item(&entry.id)?;
     if item.attachments.is_empty() { eprintln!("(no attachments)"); return Ok(()); }
-    println!("{:<17}  {:>12}  {:<22}  {}", "AID", "SIZE", "MIME", "FILENAME");
+    println!("{:<17}  {:>12}  {:<22}  FILENAME", "AID", "SIZE", "MIME");
     for a in &item.attachments {
         println!("{:<17}  {:>12}  {:<22}  {}", a.id.as_str(), a.size, a.mime_type, a.filename);
     }
@@ -2541,7 +2543,7 @@ fn cmd_device(action: DeviceAction) -> Result<()> {
                 return Ok(());
             }
 
-            println!("{:<20} {:<20} {}", "NAME", "ADDED", "SIGNING KEY (prefix)");
+            println!("{:<20} {:<20} SIGNING KEY (prefix)", "NAME", "ADDED");
             println!("{}", "-".repeat(72));
             for d in &devices {
                 let marker = if d.name == current { " *" } else { "" };