feat(plotly): implement scatter-basic (#5310)

## Implementation: `scatter-basic` - python/plotly

Implements the **python/plotly** version of `scatter-basic`.

**File:** `plots/scatter-basic/implementations/python/plotly.py`

**Parent Issue:** #611

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/24853790187)*

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

plots/scatter-basic/implementations/python/plotly.py

@@ -1,146 +1,83 @@
-""" pyplots.ai
+""" anyplot.ai
 scatter-basic: Basic Scatter Plot
-Library: plotly 6.5.2 | Python 3.14
-Quality: 92/100 | Created: 2025-12-22
+Library: plotly 6.7.0 | Python 3.14.4
+Quality: 86/100 | Created: 2026-04-23
 """
 
+import os
+
 import numpy as np
 import plotly.graph_objects as go
 
 
-# Data: Study hours vs exam scores (realistic educational context)
+# Theme tokens (see prompts/default-style-guide.md "Theme-adaptive Chrome")
+THEME = os.getenv("ANYPLOT_THEME", "light")
+PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
+ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
+INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
+INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
+GRID = "rgba(26,26,23,0.10)" if THEME == "light" else "rgba(240,239,232,0.10)"
+BRAND = "#009E73"  # Okabe-Ito position 1 — always first series
+
+# Data: study hours vs exam scores, moderate positive correlation
 np.random.seed(42)
-n_students = 120
+n_students = 160
 study_hours = np.random.uniform(1, 10, n_students)
-base_score = 45 + study_hours * 5
-exam_scores = base_score + np.random.randn(n_students) * 8
+exam_scores = 45 + study_hours * 5 + np.random.randn(n_students) * 8
 exam_scores = np.clip(exam_scores, 0, 100)
 
-# Inject outliers to show scatter plot's outlier-detection value
-study_hours[0], exam_scores[0] = 8.5, 52.0  # High effort, low result
-study_hours[1], exam_scores[1] = 2.0, 78.0  # Low effort, high result
-study_hours[2], exam_scores[2] = 9.2, 55.0  # Another underperformer
-
-# Linear regression for trend line
-coeffs = np.polyfit(study_hours, exam_scores, 1)
-trend_x = np.array([0.5, 10.5])
-trend_y = np.polyval(coeffs, trend_x)
-r_value = np.corrcoef(study_hours, exam_scores)[0, 1]
-
-# Color palette
-python_blue = "#306998"
-accent_orange = "#D4782F"
-
-fig = go.Figure()
-
-# Trend line (behind markers)
-fig.add_trace(
-    go.Scatter(
-        x=trend_x,
-        y=trend_y,
-        mode="lines",
-        line={"color": "rgba(48, 105, 152, 0.4)", "width": 2.5, "dash": "dash"},
-        showlegend=False,
-        hoverinfo="skip",
-    )
-)
-
-# Main scatter — size 11 avoids congestion in dense regions
-fig.add_trace(
+# Plot
+fig = go.Figure(
     go.Scatter(
         x=study_hours,
         y=exam_scores,
         mode="markers",
-        marker={"size": 11, "color": python_blue, "opacity": 0.6, "line": {"width": 1.2, "color": "white"}},
+        marker={"size": 13, "color": BRAND, "opacity": 0.7, "line": {"width": 1.2, "color": PAGE_BG}},
+        hovertemplate="Study: %{x:.1f} h<br>Score: %{y:.1f}%<extra></extra>",
         showlegend=False,
-        hovertemplate="<b>Student</b><br>Study: %{x:.1f} h<br>Score: %{y:.1f}%<extra></extra>",
     )
 )
 
-# Outlier diamonds
-fig.add_trace(
-    go.Scatter(
-        x=[8.5, 2.0, 9.2],
-        y=[52.0, 78.0, 55.0],
-        mode="markers",
-        marker={
-            "size": 15,
-            "color": accent_orange,
-            "opacity": 0.9,
-            "line": {"width": 2, "color": "white"},
-            "symbol": "diamond",
-        },
-        showlegend=False,
-        hoverinfo="skip",
-    )
-)
-
-# Annotations — each outlier gets its own label for clarity
-ann_base = {
-    "showarrow": True,
-    "arrowhead": 2,
-    "arrowsize": 1.2,
-    "arrowwidth": 2,
-    "arrowcolor": accent_orange,
-    "align": "center",
-    "font": {"size": 16, "color": accent_orange, "family": "Arial, sans-serif"},
-    "bgcolor": "rgba(255,255,255,0.85)",
-    "bordercolor": accent_orange,
-    "borderwidth": 1.5,
-    "borderpad": 5,
-}
-annotations = [
-    {**ann_base, "x": 2.0, "y": 78.0, "text": "Low effort,<br>high score", "ax": -75, "ay": -45},
-    {**ann_base, "x": 8.5, "y": 52.0, "text": "High effort,<br>low score", "ax": 80, "ay": 40},
-    {**ann_base, "x": 9.2, "y": 55.0, "text": "Underperformer", "ax": 75, "ay": -35},
-    # Correlation coefficient near trend line
-    {
-        "x": 8.5,
-        "y": np.polyval(coeffs, 8.5) + 4,
-        "text": f"<b>r = {r_value:.2f}</b>",
-        "showarrow": False,
-        "bgcolor": "rgba(255,255,255,0.8)",
-        "borderpad": 4,
-        "font": {"size": 17, "color": python_blue, "family": "Arial, sans-serif"},
-    },
-]
-
+# Style
 fig.update_layout(
     title={
-        "text": "scatter-basic · plotly · pyplots.ai",
-        "font": {"size": 28, "color": "#2C3E50", "family": "Arial Black, Arial, sans-serif"},
+        "text": "scatter-basic · plotly · anyplot.ai",
+        "font": {"size": 28, "color": INK},
         "x": 0.5,
         "xanchor": "center",
         "y": 0.95,
     },
     xaxis={
-        "title": {"text": "Study Hours (h)", "font": {"size": 22, "family": "Arial, sans-serif"}, "standoff": 12},
-        "tickfont": {"size": 18},
-        "showgrid": True,
+        "title": {"text": "Study Hours per Day", "font": {"size": 22, "color": INK}, "standoff": 12},
+        "tickfont": {"size": 18, "color": INK_SOFT},
+        "gridcolor": GRID,
         "gridwidth": 1,
-        "gridcolor": "rgba(0,0,0,0.06)",
-        "range": [0, 11],
+        "linecolor": INK_SOFT,
         "zeroline": False,
+        "showline": True,
+        "mirror": False,
+        "range": [0, 11],
         "dtick": 2,
     },
     yaxis={
-        "title": {"text": "Exam Score (%)", "font": {"size": 22, "family": "Arial, sans-serif"}, "standoff": 12},
-        "tickfont": {"size": 18},
-        "showgrid": True,
+        "title": {"text": "Exam Score (%)", "font": {"size": 22, "color": INK}, "standoff": 12},
+        "tickfont": {"size": 18, "color": INK_SOFT},
+        "gridcolor": GRID,
         "gridwidth": 1,
-        "gridcolor": "rgba(0,0,0,0.06)",
-        "range": [35, 105],
+        "linecolor": INK_SOFT,
         "zeroline": False,
+        "showline": True,
+        "mirror": False,
+        "range": [35, 105],
         "dtick": 10,
     },
-    template="plotly_white",
-    showlegend=False,
-    margin={"l": 80, "r": 40, "t": 90, "b": 70},
-    annotations=annotations,
-    plot_bgcolor="white",
-    paper_bgcolor="#FAFBFC",
-    hoverlabel={"bgcolor": "white", "font_size": 14, "font_color": python_blue},
+    paper_bgcolor=PAGE_BG,
+    plot_bgcolor=PAGE_BG,
+    font={"color": INK},
+    margin={"l": 90, "r": 60, "t": 100, "b": 80},
+    hoverlabel={"bgcolor": ELEVATED_BG, "bordercolor": INK_SOFT, "font": {"color": INK}},
 )
 
-fig.write_image("plot.png", width=1600, height=900, scale=3)
-fig.write_html("plot.html")
+# Save
+fig.write_image(f"plot-{THEME}.png", width=1600, height=900, scale=3)
+fig.write_html(f"plot-{THEME}.html", include_plotlyjs="cdn")