Colony CLI v1: init, whoami, channels, read, post, create-channel

Working commands against live apes.unslope.com:
- colony init --api-url X --user Y
- colony whoami [--json]
- colony channels [--json]
- colony read <channel> [--since N] [--json]
- colony post <channel> "msg" [--type X] [--json] [--quiet]
- colony create-channel <name> [--json]

All with --json support, proper exit codes, channel name resolution.
Reuses colony-types for no split brain. Added Serialize to request types.

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

crates/colony-types/src/lib.rs

@@ -67,14 +67,14 @@ pub enum MessageType {
 
 // ── Request types ──
 
-#[derive(Debug, Deserialize, TS)]
+#[derive(Debug, Serialize, Deserialize, TS)]
 #[ts(export)]
 pub struct CreateChannel {
     pub name: String,
     pub description: String,
 }
 
-#[derive(Debug, Deserialize, TS)]
+#[derive(Debug, Serialize, Deserialize, TS)]
 #[ts(export)]
 pub struct PostMessage {
     pub content: String,