BIG REFACTOR GPT SOL

feat: Refactor Iced panel adapter and introduce build metadata management

- Updated Cargo.toml files across multiple crates to use workspace versioning.
- Enhanced the `iced-panel-adapter` to include a new `plain_slider` module and updated widget rendering to support theme colors.
- Added new theme color utilities for recessed and elevated surfaces in `iced-panel-adapter`.
- Introduced a new `hcie-build-info` crate to manage build metadata, including a build ID system.
- Created a build script to synchronize build IDs across the workspace.
- Added a Makefile for simplified build commands for the Iced application.
- Implemented regression tests for vector shape creation history in the engine API.
- Added a new script for managing Cargo commands with synchronized build ID increments.
- Updated line count report to reflect recent changes in codebase.
- Created a visual plan document for future improvements in the Iced history and panel systems.

hcie-engine-api/tests/vector_creation_history.rs

@@ -0,0 +1,93 @@
+//! Regression coverage for atomic vector-shape creation history.
+//!
+//! **Purpose:** Ensures the first vector shape and its auto-created vector layer form one exact
+//! Undo/Redo transaction, while later shapes on the same layer continue to use vector snapshots.
+//! **Logic & Workflow:** Creates shapes through the public `Engine` API, inspects history metadata,
+//! and exercises Undo/Redo against layer and shape counts.
+//! **Side Effects / Dependencies:** Uses only in-memory engine documents.
+
+use hcie_engine_api::{Engine, LayerType, VectorShape};
+
+/// Builds a deterministic rectangle for history tests.
+///
+/// **Arguments:** `offset` shifts the rectangle so repeated shapes remain distinct.
+/// **Returns:** A filled vector rectangle with stable styling.
+/// **Side Effects / Dependencies:** None.
+fn rectangle(offset: f32) -> VectorShape {
+    VectorShape::Rect {
+        name: String::new(),
+        x1: 10.0 + offset,
+        y1: 12.0 + offset,
+        x2: 60.0 + offset,
+        y2: 48.0 + offset,
+        stroke: 2.0,
+        color: [10, 20, 30, 255],
+        fill: true,
+        fill_color: [40, 50, 60, 255],
+        radius: 0.0,
+        angle: 0.0,
+        opacity: 1.0,
+        hardness: 0.5,
+    }
+}
+
+#[test]
+fn first_vector_shape_is_one_atomic_layer_transaction() {
+    let mut engine = Engine::new(128, 96);
+    let layers_before = engine.get_layer_count();
+    let history_before = engine.history_len();
+
+    engine.add_vector_shape(rectangle(0.0));
+
+    assert_eq!(engine.get_layer_count(), layers_before + 1);
+    assert_eq!(engine.history_len(), history_before + 1);
+    assert_eq!(
+        engine.history_description(history_before).as_deref(),
+        Some("Add Vector Shape")
+    );
+    assert_eq!(
+        engine
+            .get_layer_info(engine.active_layer_id())
+            .map(|info| info.layer_type),
+        Some(LayerType::Vector)
+    );
+    assert_eq!(
+        engine.active_vector_shapes().map(|shapes| shapes.len()),
+        Some(1)
+    );
+
+    assert!(engine.undo());
+    assert_eq!(engine.get_layer_count(), layers_before);
+
+    assert!(engine.redo());
+    assert_eq!(engine.get_layer_count(), layers_before + 1);
+    assert!(engine
+        .layer_infos()
+        .iter()
+        .any(|info| info.layer_type == LayerType::Vector && info.shape_count == 1));
+}
+
+#[test]
+fn later_vector_shapes_each_add_one_snapshot() {
+    let mut engine = Engine::new(128, 96);
+    engine.add_vector_shape(rectangle(0.0));
+    let history_before = engine.history_len();
+
+    engine.add_vector_shape(rectangle(8.0));
+
+    assert_eq!(engine.history_len(), history_before + 1);
+    assert_eq!(
+        engine.active_vector_shapes().map(|shapes| shapes.len()),
+        Some(2)
+    );
+    assert!(engine.undo());
+    assert_eq!(
+        engine.active_vector_shapes().map(|shapes| shapes.len()),
+        Some(1)
+    );
+    assert!(engine.redo());
+    assert_eq!(
+        engine.active_vector_shapes().map(|shapes| shapes.len()),
+        Some(2)
+    );
+}