feat: Add compact AST dump

Introduce a new `dump_ast_compact` function for the environment and
Dumper. This function provides a simplified, human-readable
representation of the AST, focusing on inferred types and purity markers
instead of detailed debug information.

This change adds:
- A `compact` flag to the `Dumper` struct.
- The `dump_compact` method to the `Dumper`.
- The `dump_ast_compact` method to the `Environment`.
- A new `dump_ast_compact` command-line argument for the `ast` binary.
- A new MCP server endpoint `dump_ast_compact`.
- A `CompactMetadata` trait to abstract over different metadata types
  for compact display.
- Updates to documentation and CLI help messages.

src/bin/ast.rs

@@ -26,10 +26,14 @@ struct Cli {
     #[arg(short, long)]
     update_bench: bool,
 
-    /// Dump the compiled AST
+    /// Dump the compiled AST (verbose debug format)
     #[arg(short, long)]
     dump: bool,
 
+    /// Dump the compiled AST in compact, human-readable format (types + purity)
+    #[arg(long)]
+    dump_compact: bool,
+
     /// Run with TracingObserver enabled
     #[arg(short, long)]
     trace: bool,
@@ -129,6 +133,11 @@ fn main() {
                 Ok(dump) => println!("{}", dump),
                 Err(e) => eprintln!("Error dumping AST: {}", e),
             }
+        } else if cli.dump_compact {
+            match env.dump_ast_compact(&content) {
+                Ok(dump) => println!("{}", dump),
+                Err(e) => eprintln!("Error dumping AST: {}", e),
+            }
         } else if cli.trace {
             execute_trace(&env, &content);
         } else {