Colony CLI: inbox + ack commands

- colony inbox [--json] — show unacked inbox items
- colony ack <id> [--all] [--quiet] — ack items
- Client methods: get_inbox(), ack_inbox()
- AckRequest gets Serialize derive for CLI use

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/colony-cli/src/main.rs

@@ -56,6 +56,21 @@ enum Commands {
         #[arg(long)]
         json: bool,
     },
+    /// Check inbox (unacked mentions + activity)
+    Inbox {
+        #[arg(long)]
+        json: bool,
+    },
+    /// Acknowledge inbox items
+    Ack {
+        /// Inbox item IDs to ack
+        ids: Vec<i64>,
+        /// Ack all unacked items
+        #[arg(long)]
+        all: bool,
+        #[arg(long)]
+        quiet: bool,
+    },
     /// Initialize .colony.toml
     Init {
         #[arg(long)]
@@ -172,6 +187,43 @@ async fn run_command(cmd: Commands, client: &ColonyClient) {
             }
         }
 
+        Commands::Inbox { json } => {
+            let items = client.get_inbox().await;
+            if json {
+                println!("{}", serde_json::to_string(&items).unwrap());
+            } else if items.is_empty() {
+                println!("inbox empty");
+            } else {
+                for item in &items {
+                    println!("[{}] #{} [{}] {}: {} ({})",
+                        item.id,
+                        item.channel_name,
+                        item.message.seq,
+                        item.message.user.username,
+                        item.message.content,
+                        item.trigger,
+                    );
+                }
+            }
+        }
+
+        Commands::Ack { ids, all, quiet } => {
+            let to_ack = if all {
+                let items = client.get_inbox().await;
+                items.iter().map(|i| i.id).collect::<Vec<_>>()
+            } else {
+                ids
+            };
+            if to_ack.is_empty() {
+                if !quiet { println!("nothing to ack"); }
+            } else {
+                let result = client.ack_inbox(&to_ack).await;
+                if !quiet {
+                    println!("acked {} items", result["acked"]);
+                }
+            }
+        }
+
         Commands::Init { .. } => unreachable!(),
     }
 }