feat(gateway): full Telegram+Discord integration with agent loop

Complete multi-platform gateway wiring:

config:
- [platform.telegram] section with bot_token
- [platform.discord] section with bot_token + guild_id
- Threaded through GyandootConfig → AgentConfig via typed structs

gateway:
- GatewayRunner::new(platforms) takes Vec<Box<dyn Platform>>
- start() spawns all platform pollers, merges receivers
- serve(agent) runs full message loop: receive → access control →
  typing indicator → session_turn() → platform.send()
- Ctrl+C graceful shutdown via tokio::select!

cmd_serve now:
1. Loads config, creates agent
2. Builds Telegram + Discord adapters from config
3. Starts gateway pollers
4. Enters serve loop until Ctrl+C

crates/gyandoot-core/src/config.rs

@@ -131,9 +131,12 @@ pub struct PlatformSection {
     /// Default platform (e.g. "cli", "telegram", "discord").
     #[serde(default = "default_platform_default")]
     pub default: String,
-    /// Platform-specific config (flattened for extensibility).
-    #[serde(default, flatten)]
-    pub platforms: HashMap<String, toml::Value>,
+    /// Telegram bot configuration.
+    #[serde(default)]
+    pub telegram: Option<TelegramPlatformCfg>,
+    /// Discord bot configuration.
+    #[serde(default)]
+    pub discord: Option<DiscordPlatformCfg>,
 }
 
 fn default_platform_default() -> String {
@@ -144,11 +147,31 @@ impl Default for PlatformSection {
     fn default() -> Self {
         Self {
             default: default_platform_default(),
-            platforms: HashMap::new(),
+            telegram: None,
+            discord: None,
         }
     }
 }
 
+/// Telegram bot config as written in [platform.telegram] section.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct TelegramPlatformCfg {
+    /// Bot token from @BotFather.
+    #[serde(default)]
+    pub bot_token: String,
+}
+
+/// Discord bot config as written in [platform.discord] section.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DiscordPlatformCfg {
+    /// Bot token from Discord Developer Portal.
+    #[serde(default)]
+    pub bot_token: String,
+    /// Optional guild ID for channel discovery.
+    #[serde(default)]
+    pub guild_id: Option<u64>,
+}
+
 /// `[memory]` section.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct MemorySection {
@@ -343,8 +366,14 @@ impl From<GyandootConfig> for AgentConfig {
             },
             platform: PlatformRootConfig {
                 default: cfg.platform.default,
-                telegram: None,
-                discord: None,
+                telegram: cfg.platform.telegram.map(|t| TelegramConfig {
+                    bot_token: t.bot_token,
+                    allowed_users: Vec::new(),
+                }),
+                discord: cfg.platform.discord.map(|d| DiscordConfig {
+                    bot_token: d.bot_token,
+                    guild_id: d.guild_id,
+                }),
                 webhook: None,
             },
             memory: MemoryRootConfig {

crates/gyandoot-core/src/lib.rs

@@ -11,11 +11,11 @@ pub mod service;
 
 pub use config::{
     AgentConfig, AgentSection, AnthropicConfig, BrowserSection, ConfigLoader,
-    GatewaySection, GyandootConfig, IdentitySection,
+    DiscordPlatformCfg, GatewaySection, GyandootConfig, IdentitySection,
     KanbanRootConfig, MemoryRootConfig, MemorySection, OllamaConfig,
     OpenAIConfig, PlatformRootConfig, PlatformSection, ProviderRootConfig,
     ProvidersSection, SecurityRootConfig, SkillsRootConfig, TelegramConfig,
-    WebhookConfig, DiscordConfig, load_config_from_file,
+    TelegramPlatformCfg, WebhookConfig, DiscordConfig, load_config_from_file,
 };
 pub use error::*;
 pub use types::*;