Slash commands (/quit, /help) + zero compiler warnings

1. /quit and /help commands restored:
   - /quit: exits the interactive loop
   - /help: shows formatted help box with available commands & tips
   - Unknown commands get a friendly error pointing to /help
   - Slash commands intercepted before LLM processing (no token waste)

2. Zero warnings across entire workspace (13 files fixed):
   - Fixed ambiguous glob re-exports in gyandoot-core
   - Added #[allow(dead_code)] on intentional dead fields
   - Fixed unused imports, variables, and macros
   - Fixed unused assignments in subagents
   - cleaned up service.rs, profile, kanban warnings

install.sh now produces a completely clean build with zero warnings.

crates/gyandoot-agent/src/agent_loop.rs

@@ -25,6 +25,7 @@ use crate::context::ContextCompressor;
 use crate::tools::ToolExecutor;
 
 // ─── CLI color constants ──────────────────────────────────────────────
+#[allow(dead_code)]
 mod cli_color {
     pub const RESET: &str = "\x1b[0m";
     pub const BOLD: &str = "\x1b[1m";
@@ -143,6 +144,7 @@ pub struct AgentLoop {
     sanitizer: Sanitizer,
     status: Arc<Mutex<AgentStatus>>,
     retry_cfg: RetryConfig,
+    #[allow(dead_code)]
     browser_client: Option<BrowserClient>,
 }
 
@@ -204,7 +206,7 @@ impl AgentLoop {
         // ── Identity & memory injection on startup ─────────────────────
         let (agent_name, agent_role, user_name, user_role) = {
             let memory = self.memory.lock().await;
-            let (l0, _) = memory.identity_get().unwrap_or_default();
+            let (_l0, _) = memory.identity_get().unwrap_or_default();
 
             // Priority: config identity > config.agent.name > defaults
             let a_name = if !self.config.identity.agent_name.is_empty() {
@@ -267,7 +269,16 @@ impl AgentLoop {
             // 1. Read user input
             let user_input = self.read_input().await?;
 
-            // 2. Check exit conditions
+            // 2. Handle built-in slash commands
+            if user_input.starts_with('/') {
+                let should_quit = self.handle_command(&user_input).await;
+                if should_quit {
+                    break;
+                }
+                continue;
+            }
+
+            // 3. Check exit conditions
             if self.should_exit(&user_input) {
                 info!("User requested exit");
                 break;
@@ -619,7 +630,49 @@ impl AgentLoop {
 
     /// Check if the user wants to exit.
     fn should_exit(&self, input: &str) -> bool {
-        matches!(input.to_lowercase().as_str(), "exit" | "quit" | "bye")
+        matches!(input.to_lowercase().as_str(), "exit" | "quit" | "bye" | "/quit")
+    }
+
+    /// Handle a slash command. Returns true if the user wants to exit.
+    async fn handle_command(&self, cmd: &str) -> bool {
+        match cmd.to_lowercase().as_str() {
+            "/quit" | "/exit" => {
+                info!("User requested exit via slash command");
+                true
+            }
+            "/help" => {
+                println!(
+                    "\n{bold}{cyan}╔════════════════════════════════════╗\
+                     \n║        GyanDoot — Help              ║\
+                     \n╚════════════════════════════════════╝{reset}\n\
+                     \n{bold}Commands:{reset}\
+                     \n  {green}»{reset}  Type anything to chat with the AI\
+                     \n  {green}/quit{reset}   Exit GyanDoot\
+                     \n  {green}/help{reset}   Show this help message\n\
+                     \n{bold}Tips:{reset}\
+                     \n  • Use {cyan}web_search{reset} for online queries\
+                     \n  • Use {cyan}web_browse{reset} to visit websites\
+                     \n  • Type {yellow}exit{reset}, {yellow}quit{reset}, or {yellow}bye{reset} to exit\n",
+                    bold = cli_color::BOLD,
+                    cyan = cli_color::BRIGHT_CYAN,
+                    green = cli_color::GREEN,
+                    yellow = cli_color::YELLOW,
+                    reset = cli_color::RESET,
+                );
+                false
+            }
+            _ => {
+                println!(
+                    "\n{yellow}Unknown command:{reset} {cmd}\n\
+                     Type {green}/help{reset} for available commands.\n",
+                    yellow = cli_color::YELLOW,
+                    reset = cli_color::RESET,
+                    cmd = cmd,
+                    green = cli_color::GREEN,
+                );
+                false
+            }
+        }
     }
 }