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-core/src/lib.rs

@@ -9,6 +9,13 @@ pub mod config;
 pub mod error;
 pub mod service;
 
-pub use types::*;
-pub use config::*;
-pub use error::*;
+pub use config::{
+    AgentConfig, AgentSection, AnthropicConfig, BrowserSection, ConfigLoader,
+    GatewaySection, GyandootConfig, IdentitySection,
+    KanbanRootConfig, MemoryRootConfig, MemorySection, OllamaConfig,
+    OpenAIConfig, PlatformRootConfig, PlatformSection, ProviderRootConfig,
+    ProvidersSection, SecurityRootConfig, SkillsRootConfig, TelegramConfig,
+    WebhookConfig, DiscordConfig, load_config_from_file,
+};
+pub use error::*;
+pub use types::*;