Consistency Refactoring

All 6 consistency review items have been resolved, verified with new
unit tests, automated test suites, and clean example builds.

- **Fixed `Goto` Duration Bug**: In
  [`turtle-lib/src/command_behavior.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/command_behavior.rs),
  mapped Cartesian target coordinates to screen space (`vec2(target.x,
  -target.y)`) before calculating $\Delta x$ and $\Delta y$ in
  `animation_duration`.
- **Unit Test**: Added `test_goto_duration_cartesian_inversion` testing
  that moving from screen $(0, 100)$ (Cartesian $(0, -100)$) to
  Cartesian $(0, 100)$ computes duration based on the actual 200px
  Euclidean distance ($2.0\text{s}$ at $100\text{ px/s}$).

- **Stored `Degrees`**: Updated `TurtleCommand::SetHeading(Degrees)` in
  [`turtle-lib/src/commands.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/commands.rs)
  to store user degrees directly ($0^\circ = \text{East}$, $90^\circ =
  \text{North}$), matching `Turn(Degrees)` and `Circle { angle: Degrees
  }`.
- **Deferred Screen-Space Conversion**: Converted to internal screen
  radians (`normalize_angle(-heading.as_radians().value())`) inside
  `apply_to_params` in
  [`turtle-lib/src/command_behavior.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/command_behavior.rs).
- **Instant Duration**: Maintained instant transition ($0.01\text{s}$
  minimum) in `animation_duration`.
- **Unit Test**: Added `test_set_heading_degrees_and_instant_duration`
  verifying $90^\circ$ maps to North ($-\frac{\pi}{2}$ in screen space),
  $0^\circ$ to East ($0$), $270^\circ$ to South ($+\frac{\pi}{2}$), and
  duration is $0.01\text{s}$.

- **Enhanced `Length` Type**: Expanded
  [`turtle-lib/src/general/length.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/general/length.rs)
  with `new()`, `value()`, `Neg`, `PartialOrd`, and conversion
  implementations (`From<f32>`, `From<f64>`, `From<i32>`, `From<i16>`,
  `From<usize>`).
- **Adopted Across API**:
  - `TurtleCommand::Move(Length)` in `commands.rs`.
  - `TurtleCommand::Circle { radius: Length, ... }` in `commands.rs`.
  - `forward<T: Into<Length>>` and `backward<T: Into<Length>>` in
    [`turtle-lib/src/builders.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/builders.rs).
  - `circle_left`, `circle_right` accept `radius: impl Into<Length>`.
  - Kept stroke attribute `pen_width` as `Precision` (`f32`).
- **Unit Test**: Added `test_length_conversions_and_negation` in
  `general::length`.

- **Removed Duplicate Alias**: Removed `all_animations_complete(&self)`
  from `TurtleApp` in
  [`turtle-lib/src/lib.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/lib.rs);
  updated call in
  [`turtle-lib/src/export.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/src/export.rs)
  to use canonical `is_complete(&self)`.
- **Corrected
  [`README.md`](file:///home/dietrich/Projekte/Source/turtlers/README.md)**:
  - `plan.goto(...)` $\rightarrow$ `plan.go_to(...)`
  - `plan.set_color(...)` $\rightarrow$ `plan.set_pen_color(...)`
  - `create_turtle()` $\rightarrow$ `create_turtle_plan()`
- **Corrected
  [`AGENTS.md`](file:///home/dietrich/Projekte/Source/turtlers/AGENTS.md)**:
  - `create_turtle()` $\rightarrow$ `create_turtle_plan()` in Threading
    Pattern.

- **Unified on `1000.0`**:
  - Updated
    [`README.md`](file:///home/dietrich/Projekte/Source/turtlers/README.md)
    lines 9, 108, 109 to state `speed >= 1000` is Instant and `speed <
    1000` is Animated.
  - Updated
    [`turtle-lib/examples/circle_test.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/examples/circle_test.rs)
    to use `turtle.set_speed(1000)`.

- **Renamed Examples**:
  - `turtle-lib/examples/stern.rs` $\rightarrow$
    [`turtle-lib/examples/star.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/examples/star.rs)
  - `turtle-lib/examples/nikolaus.rs` $\rightarrow$
    [`turtle-lib/examples/house_of_nikolaus.rs`](file:///home/dietrich/Projekte/Source/turtlers/turtle-lib/examples/house_of_nikolaus.rs)
- **Translated Functions & Parameters**:
  - `house_of_nikolaus.rs`: Translated `nikolausquadrat` $\rightarrow$
    `house_square`, `nikolausdiag` $\rightarrow$ `house_diagonal`,
    `nikolausdach2` $\rightarrow$ `house_roof`, parameter `groesse`
    $\rightarrow$ `size`. Added doc comment explaining the Eulerian path
    puzzle.
  - `breadboard.rs`: Translated `pin_reihe` $\rightarrow$ `pin_row`,
    `pin_spalte` $\rightarrow$ `pin_column`, `pin_seite` $\rightarrow$
    `pin_side`, parameter `anzahl` $\rightarrow$ `count`,
    `anzahl_reihen` $\rightarrow$ `row_count`. Added `#[cfg(feature =
    "svg")]` to helper functions to eliminate dead-code warnings when
    SVG feature is not enabled.
- **Translated UI Text & Print Messages**:
  - `"Drücke E für SVG-Export"` $\rightarrow$ `"Press E for SVG export"`
  - `"SVG exportiert nach test.svg"` $\rightarrow$ `"SVG exported to
    test.svg"`
  - `"Fehler beim Export: {:?}"` $\rightarrow$ `"Export error: {:?}"`
  - `"SVG-Export ist nicht aktiviert..."` $\rightarrow$ `"SVG export is
    not enabled..."`
  - Translated module doc in `export_svg.rs`.
- **Updated
  [`README.md`](file:///home/dietrich/Projekte/Source/turtlers/README.md)**
  example lists and CLI commands to reference `star` and
  `house_of_nikolaus`.

---

- `cargo test --package turtle-lib`:
  - 13 unit tests passed (including 3 new targeted unit tests)
  - 34 doctests passed (1 ignored internal helper)
- `cargo check --workspace --all-targets --all-features`: Passed with 0
  errors.
- `cargo check --examples --package turtle-lib --all-features`: All 30
  examples compiled cleanly with 0 errors.
- `cargo clippy --package turtle-lib -- -Wclippy::pedantic
  -Aclippy::cast_precision_loss -Aclippy::cast_sign_loss
  -Aclippy::cast_possible_truncation`: Passed with 0 errors.

turtle-lib/examples/star.rs

@@ -0,0 +1,21 @@
+//! Star pattern example demonstrating complex turtle patterns
+
+use turtle_lib::*;
+
+#[turtle_main("Star Pattern")]
+fn draw(turtle: &mut TurtlePlan) {
+    turtle.shape(ShapeType::Turtle);
+    turtle.set_speed(1500);
+    turtle.set_pen_width(0.5);
+
+    // Draw a 5-pointed star pattern repeatedly
+    for _i in 0..50000 {
+        turtle.forward(200.0);
+        turtle.circle_left(10.0, 72.0, 1000);
+        turtle.circle_right(5.0, 360.0, 1000);
+        turtle.circle_left(10.0, 72.0, 1000);
+    }
+
+    // Set animation speed
+    turtle.set_speed(300);
+}