docs: Add Rustdoc for modules, functions, and structs

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/args.rs

@@ -3,9 +3,7 @@ use std::str::FromStr;
 
 use clap::*;
 
-/**
- * Main struct for command-line arguments.
- */
+/// Main struct for command-line arguments, parsed via Clap.
 #[derive(Parser, Debug, Clone)]
 #[command(author, version, about, long_about = None)]
 pub struct Args {
@@ -22,9 +20,7 @@ pub struct Args {
     pub ids_or_tags: Vec<NumberOrString>,
 }
 
-/**
- * Struct for mode-specific arguments.
- */
+/// Struct for mode-specific arguments, defining CLI flags for different operations.
 #[derive(Parser, Debug, Clone)]
 pub struct ModeArgs {
     #[arg(group("mode"), help_heading("Mode Options"), short, long, conflicts_with_all(["get", "diff", "list", "delete", "info", "status"]))]
@@ -82,9 +78,7 @@ pub struct ModeArgs {
     pub server_port: Option<u16>,
 }
 
-/**
- * Struct for item-specific arguments.
- */
+/// Struct for item-specific arguments, such as compression and plugins.
 #[derive(Parser, Debug, Clone)]
 pub struct ItemArgs {
     #[arg(help_heading("Item Options"), short, long, env("KEEP_COMPRESSION"))]
@@ -101,9 +95,7 @@ pub struct ItemArgs {
 }
 
 
-/**
- * Struct for general options.
- */
+/// Struct for general options, including verbosity, paths, and output settings.
 #[derive(Parser, Debug, Default, Clone)]
 pub struct OptionsArgs {
     #[arg(long, env("KEEP_CONFIG"))]
@@ -150,11 +142,7 @@ pub struct OptionsArgs {
     pub force: bool,
 }
 
-use derive_more::From;
-
-/**
- * Enum for representing either a number or a string.
- */
+/// Enum for representing either a number (item ID) or a string (tag).
 #[derive(Debug, Clone, From)]
 pub enum NumberOrString {
     Number(i64),
@@ -170,6 +158,11 @@ impl FromStr for NumberOrString {
     }
 }
 
+/// Validates the parsed arguments based on mode constraints.
+///
+/// # Returns
+///
+/// `Result<(), String>` - Ok if valid, or an error message string.
 impl Args {
     /// Validate the arguments based on the selected mode
     pub fn validate(&self) -> Result<(), String> {