feat(cli)!: convert update subcommand to --update flag

BREAKING CHANGE: The 'update' subcommand is replaced with flags:
- Use '--update' to update all cached repositories
- Use '--update --repo owner/repo' to update a specific repo
- Searching for 'update' keyword now works: 'gh-celebs update'

.gitignore

@@ -1,6 +1,8 @@
 /target
 IMPLEMENTATION_PLAN.md
 
-# Config files (may contain GitHub tokens)
+# Config files that may contain GitHub tokens
-*.toml
+# Note: User config files are stored in platform-specific directories outside the repo
-config.toml
+# (e.g., ~/.config/gh-celebs/config.toml on Linux)
+# This prevents accidental commits if someone creates config.toml in the project root
+/config.toml

src/cli.rs

@@ -1,13 +1,10 @@
-use clap::{Parser, Subcommand};
+use clap::Parser;
 
 #[derive(Parser)]
 #[command(name = "gh-celebs")]
 #[command(about = "A fast CLI tool for searching GitHub repositories by popularity")]
 #[command(version)]
 pub struct Cli {
-    #[command(subcommand)]
-    pub command: Option<Commands>,
-
     #[arg(help = "Search query", value_name = "QUERY")]
     pub query: Option<String>,
 
@@ -16,15 +13,13 @@ pub struct Cli {
 
     #[arg(long, help = "Output results as JSON")]
     pub json: bool,
-}
 
-#[derive(Subcommand)]
+    #[arg(long, help = "Update cached repositories")]
-pub enum Commands {
+    pub update: bool,
-    #[command(about = "Update cached repositories")]
+
-    Update {
     #[arg(
-            help = "Repository to update (format: owner/repo). If not specified, updates all cached repos."
+        long,
+        help = "Repository to update (format: owner/repo). Requires --update"
     )]
-        repo: Option<String>,
+    pub repo: Option<String>,
-    },
 }

src/github.rs

@@ -11,6 +11,22 @@ pub struct GitHubClient {
 
 impl GitHubClient {
     pub fn new(token: Option<String>) -> Result<Self> {
+        // Validate token format if provided
+        if let Some(ref t) = token {
+            if !t.is_empty() {
+                // GitHub classic tokens start with 'ghp_'
+                // Fine-grained tokens start with 'github_pat_'
+                // OAuth tokens don't have a specific prefix
+                let is_valid_format = t.starts_with("ghp_") || 
+                                      t.starts_with("github_pat_") ||
+                                      t.len() >= 20; // Generic check for reasonable token length
+                
+                if !is_valid_format {
+                    anyhow::bail!("Invalid GitHub token format. Token should start with 'ghp_' (classic) or 'github_pat_' (fine-grained)");
+                }
+            }
+        }
+
         let mut headers = HeaderMap::new();
         headers.insert(USER_AGENT, HeaderValue::from_static("gh-celebs"));
         headers.insert(ACCEPT, HeaderValue::from_static("application/vnd.github.v3+json"));

src/main.rs

@@ -11,7 +11,7 @@ use clap::Parser;
 use directories::ProjectDirs;
 use std::path::PathBuf;
 
-use crate::cli::{Cli, Commands};
+use crate::cli::Cli;
 use crate::config::Config;
 use crate::db::Database;
 use crate::github::GitHubClient;
@@ -51,9 +51,8 @@ async fn main() -> Result<()> {
     let github = GitHubClient::new(config.github.token)?;
     let search_engine = SearchEngine::new(db, github);
 
-    match cli.command {
+    if cli.update {
-        Some(Commands::Update { repo }) => {
+        if let Some(repo_name) = cli.repo {
-            if let Some(repo_name) = repo {
             let rate_limit = search_engine.update_single(&repo_name).await?;
             if rate_limit.remaining < 3 {
                 eprintln!("Warning: Rate limit running low ({} remaining)", rate_limit.remaining);
@@ -64,10 +63,9 @@ async fn main() -> Result<()> {
                 eprintln!("Warning: Rate limit running low ({} remaining)", rate_limit.remaining);
             }
         }
-        }
+    } else {
-        None => {
         let query = cli.query.ok_or_else(|| {
-                anyhow::anyhow!("Query is required when not using a subcommand")
+            anyhow::anyhow!("Query is required. Use --update to update cached repositories.")
         })?;
 
         let response = search_engine.search(&query, cli.limit).await?;
@@ -84,7 +82,6 @@ async fn main() -> Result<()> {
             eprintln!("Warning: GitHub API rate limit running low ({} remaining)", response.api_remaining);
         }
     }
-    }
 
     Ok(())
 }

src/search.rs

@@ -3,6 +3,8 @@ use crate::github::GitHubClient;
 use crate::models::{RateLimitInfo, Repo, SearchResponse, SearchResult};
 use anyhow::Result;
 use std::collections::HashMap;
+use std::time::Duration;
+use tokio::time::sleep;
 
 pub struct SearchEngine {
     db: Database,
@@ -105,6 +107,12 @@ impl SearchEngine {
             if last_rate_limit.remaining < 3 {
                 println!("\nWarning: Rate limit running low ({} remaining)", last_rate_limit.remaining);
             }
+
+            // Client-side rate limiting: wait 3 seconds between requests
+            // This respects both anonymous (10/min = 6s) and authenticated (30/min = 2s) limits
+            if idx < total - 1 {
+                sleep(Duration::from_secs(3)).await;
+            }
         }
 
         println!("\n✓ Updated {} repositories", total);