docs: tambah doc comment, logging, dan inline comments di semua 255 file

Meliputi:
- File-level //! doc comment: tujuan file, alur kerja, komponen utama
- Function-level /// doc comment: apa, parameter, return, flow, edge cases
- Struct/enum/trait /// doc comment: peran, field docs
- Tracing logging (tracing::info!/debug!/trace!/warn!/error!) di setiap fungsi
- Inline comments untuk variable dan branching logic penting
- Seluruh 8 crates di workspace: zesdex-backend, zesdex-cms, zesdex-entities,
  zesdex-iam, zesdex-infra, zesdex-ipc, zesdex-middleware, zesdex-utils
- Build: 0 errors, 242/242 tests passed

crates/zesdex-infra/src/password.rs

@@ -10,6 +10,7 @@ use argon2::{
     Argon2,
 };
 use rand_core::OsRng;
+use tracing;
 
 /// Hash a plaintext password using Argon2id with a random salt.
 ///
@@ -21,11 +22,12 @@ use rand_core::OsRng;
 /// Returns an error if the argon2 library fails (extremely rare —
 /// typically indicates an OOM or system-level crypto failure).
 pub fn hash_password(password: &str) -> Result<String> {
-    let salt = SaltString::generate(&mut OsRng);
-    let argon2 = Argon2::default();
+    let salt = SaltString::generate(&mut OsRng); // cryptographic random salt
+    let argon2 = Argon2::default(); // Argon2id with default params
     let hash = argon2
         .hash_password(password.as_bytes(), &salt)
         .map_err(|e| anyhow::anyhow!("failed to hash password: {e}"))?;
+    tracing::debug!("password hashed successfully");
     Ok(hash.to_string())
 }
 
@@ -41,10 +43,12 @@ pub fn hash_password(password: &str) -> Result<String> {
 pub fn verify_password(password: &str, hash: &str) -> Result<bool> {
     let parsed_hash = PasswordHash::new(hash)
         .map_err(|e| anyhow::anyhow!("failed to parse password hash: {e}"))?;
-    let argon2 = Argon2::default();
-    Ok(argon2
+    let argon2 = Argon2::default(); // Argon2id with default params
+    let valid = argon2
         .verify_password(password.as_bytes(), &parsed_hash)
-        .is_ok())
+        .is_ok();
+    tracing::debug!("password verification result: {valid}");
+    Ok(valid)
 }
 
 #[cfg(test)]