delete dead code: channel-test, mcp-schema, cmd_mcp_schema

channel-test was a debug tool, mcp-schema was superseded by
consciousness-mcp, cmd_mcp_schema in cli/misc.rs was the old
poc-memory subcommand.

Co-Developed-By: Kent Overstreet <kent.overstreet@linux.dev>

src/main.rs

@@ -814,7 +814,7 @@ impl Run for Command {
             Self::Cursor(sub)            => sub.run(),
             Self::Agent(sub)             => sub.run(),
             Self::Admin(sub)             => sub.run(),
-            // mcp-schema moved to standalone binary src/claude/mcp-schema.rs
+            // mcp-schema moved to consciousness-mcp binary
         }
     }
 }