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-browser/src/client.rs

@@ -14,7 +14,7 @@ use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
 use tokio::net::UnixStream;
-use tracing::{debug, info, warn};
+use tracing::{debug, warn};
 
 // ─── Constants ──────────────────────────────────────────────────────────
 
@@ -101,6 +101,7 @@ struct DaemonCommand {
 /// A response from the daemon.
 #[derive(Debug, Deserialize)]
 struct DaemonResponse {
+    #[allow(dead_code)]
     id: String,
     success: bool,
     #[serde(default)]