Implement Misses DSL compiler (parser + codegen)

- ast.rs: Full AST for .mrs files (MacroDef, Pattern, OutputBody, TemplateItem)
- parser.rs: Hand-written recursive descent parser with line/col error reporting
- codegen.rs: Transforms AST to Rust proc macro code using syn/quote/proc_macro2
- main.rs: CLI reads .mrs file, runs parse→codegen, writes to stdout or file
- Cargo.toml: Workspace with syn, quote, proc-macro2, prettyplease deps
- examples/: hello.mrs, derive_builder.mrs, declare_table.mrs reference examples

All three reference examples parse and produce prettyplease-formatted Rust output.
Generated code uses syn::parse::Parser closures for structural patterns, quote!
for token templates, spread iteration via .iter().map().collect(), and
format_ident! for identifier construction.

https://claude.ai/code/session_01Tppkab4eLsL21asHGjQJoF

examples/declare_table.mrs

@@ -0,0 +1,15 @@
+macro declare_table! {
+    $name:ident { $body:tt } => {
+        @{
+            let table_str = misses_rt::to_table_name(&name);
+        }
+        T~{
+            pub struct $name {
+                pub id: u64,
+            }
+            impl $name {
+                pub const TABLE: &'static str = ${ table_str.as_str() };
+            }
+        }
+    }
+}