Add egui_extras dependency

Adds `egui_extras` to Cargo.toml and Cargo.lock to enable enhanced table
widgets.
Also introduces a new `StateTab` enum and integrates the
`egui_extras::TableBuilder` to display global variables in a structured
table within the application's state panel. This enhances the debugging
and introspection capabilities of the compiler UI by providing a clear
view of the environment's global state.

src/main.rs

@@ -1,4 +1,5 @@
 use eframe::egui;
+use egui_extras::{Column, TableBuilder};
 use myc::ast::compiler::emitter;
 use myc::ast::environment::Environment;
 use myc::ast::parser::Parser;
@@ -29,6 +30,13 @@ enum AppTab {
     Trace,
 }
 
+#[derive(PartialEq)]
+enum StateTab {
+    Globals,
+    Dataflow,
+    Series,
+}
+
 struct CompilerApp {
     source_code: String,
     current_example_path: Option<PathBuf>,
@@ -38,6 +46,7 @@ struct CompilerApp {
     trace_logs: Vec<String>,
     active_tab: AppTab,
     debug_enabled: bool,
+    state_tab: StateTab,
     env: Environment,
     is_first_frame: bool,
     examples: Vec<Example>,
@@ -86,6 +95,7 @@ impl Default for CompilerApp {
             trace_logs: Vec::new(),
             active_tab: AppTab::Output,
             debug_enabled: false,
+            state_tab: StateTab::Globals,
             env,
             is_first_frame: true,
             examples,
@@ -573,6 +583,75 @@ impl eframe::App for CompilerApp {
                 }
             });
 
+        // Right Side Panel: Environment State Inspector
+        egui::SidePanel::right("state_panel")
+            .resizable(true)
+            .default_width(300.0)
+            .min_width(200.0)
+            .show(ctx, |ui| {
+                ui.horizontal(|ui| {
+                    ui.selectable_value(&mut self.state_tab, StateTab::Globals, "Globals");
+                    ui.selectable_value(&mut self.state_tab, StateTab::Dataflow, "Dataflow");
+                    ui.selectable_value(&mut self.state_tab, StateTab::Series, "Series");
+                });
+                ui.separator();
+
+                match self.state_tab {
+                    StateTab::Globals => {
+                        let globals = self.env.list_user_globals();
+                        let scopes = self.env.root_scopes.borrow();
+                        let rtl_slots = self.env.rtl.slot_count;
+                        let total_slots = *self.env.root_slot_count.borrow();
+                        let scope_details: Vec<String> = scopes.iter().enumerate().map(|(i, s)| {
+                            let entries: Vec<String> = s.locals.iter().map(|(sym, info)| {
+                                format!("{}={:?}", sym.name, info.addr)
+                            }).collect();
+                            format!("S{}[{}]", i, entries.join(", "))
+                        }).collect();
+                        drop(scopes);
+                        ui.label(format!(
+                            "DEBUG: rtl={}, total={}, found={}", rtl_slots, total_slots, globals.len()
+                        ));
+                        for s in &scope_details {
+                            ui.label(s);
+                        }
+                        if globals.is_empty() {
+                            ui.label("No user globals. Run a script first.");
+                        } else {
+                            let available = ui.available_height();
+                            TableBuilder::new(ui)
+                                .striped(true)
+                                .resizable(true)
+                                .cell_layout(egui::Layout::left_to_right(egui::Align::Center))
+                                .min_scrolled_height(available)
+                                .column(Column::auto().at_least(60.0))
+                                .column(Column::auto().at_least(60.0))
+                                .column(Column::remainder().at_least(80.0))
+                                .header(18.0, |mut header| {
+                                    header.col(|ui| { ui.strong("Name"); });
+                                    header.col(|ui| { ui.strong("Type"); });
+                                    header.col(|ui| { ui.strong("Value"); });
+                                })
+                                .body(|mut body| {
+                                    for (name, ty, val) in &globals {
+                                        body.row(18.0, |mut row| {
+                                            row.col(|ui| { ui.monospace(name); });
+                                            row.col(|ui| { ui.monospace(ty.to_string()); });
+                                            row.col(|ui| { ui.monospace(val.to_string()); });
+                                        });
+                                    }
+                                });
+                        }
+                    }
+                    StateTab::Dataflow => {
+                        ui.label("Stream/Pipe dataflow graph will appear here after execution.");
+                    }
+                    StateTab::Series => {
+                        ui.label("Series contents will appear here after execution.");
+                    }
+                }
+            });
+
         // Central Panel: Source Code Editor (Fills remaining space)
         egui::CentralPanel::default().show(ctx, |ui| {
             ui.heading("Source Code Editor");