Feat: DIST / ID / AREA inquiry commands

Add three classic CAD measurement commands:
- DIST (DI): two-point pick → distance, angle, delta XYZ
- ID: one-point pick → coordinates
- AREA: multi-point polygon pick (Enter to close) → area + perimeter

New CmdResult::Measurement(String) variant ends active command and
prints result to command line without modifying the document.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/modules/home/inquiry/id.rs

@@ -0,0 +1,36 @@
+// ID command — report coordinates of a picked point.
+
+use glam::Vec3;
+
+use crate::command::{CadCommand, CmdResult};
+
+pub struct IdCommand;
+
+impl IdCommand {
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl CadCommand for IdCommand {
+    fn name(&self) -> &'static str {
+        "ID"
+    }
+
+    fn prompt(&self) -> String {
+        "ID  Specify point:".into()
+    }
+
+    fn on_point(&mut self, pt: Vec3) -> CmdResult {
+        // Y-up world: X stays X, Z→drawing Y, Y→elevation Z
+        let x = pt.x;
+        let y = pt.z;
+        let z = pt.y;
+        let msg = format!("X = {x:.4},  Y = {y:.4},  Z = {z:.4}");
+        CmdResult::Measurement(msg)
+    }
+
+    fn on_enter(&mut self) -> CmdResult {
+        CmdResult::Cancel
+    }
+}