feat(plotly): implement ecdf-basic (#9485)

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

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

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

**Parent Issue:** #976

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/28160341179)*

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Markus Neusinger <2921697+MarkusNeusinger@users.noreply.github.com>

Author: github-actions[bot]

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

@@ -1,10 +1,16 @@
 """ anyplot.ai
 ecdf-basic: Basic ECDF Plot
-Library: plotly 6.7.0 | Python 3.14.4
-Quality: 88/100 | Updated: 2026-04-24
+Library: plotly 6.8.0 | Python 3.13.14
+Quality: 88/100 | Updated: 2026-06-25
 """
 
 import os
+import sys
+
+
+# Remove the script's own directory from sys.path so this file doesn't shadow
+# the installed plotly package (script is named plotly.py).
+sys.path = [p for p in sys.path if p not in ("", os.path.dirname(os.path.abspath(__file__)))]
 
 import numpy as np
 import plotly.graph_objects as go
@@ -16,58 +22,97 @@
 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
+GRID = "rgba(26,26,23,0.15)" if THEME == "light" else "rgba(240,239,232,0.15)"
+BRAND = "#009E73"  # Imprint palette position 1 — always first series
+ANYPLOT_AMBER = "#DDCC77"  # annotation accent
 
-# Data: marathon finishing times (minutes) for 300 runners
+# Data: HTTP API response latencies (ms) for 400 requests to a web service
 np.random.seed(42)
-n_runners = 300
-finish_times = np.random.normal(loc=240, scale=32, size=n_runners)
+n_requests = 400
+# Lognormal distribution models real-world latency well (long right tail)
+latency_ms = np.random.lognormal(mean=4.8, sigma=0.5, size=n_requests)
 
 # ECDF
-sorted_times = np.sort(finish_times)
-cumulative_proportion = np.arange(1, n_runners + 1) / n_runners
+sorted_latency = np.sort(latency_ms)
+cumulative_proportion = np.arange(1, n_requests + 1) / n_requests
+
+# Key percentiles
+p50 = np.percentile(sorted_latency, 50)
+p90 = np.percentile(sorted_latency, 90)
+p99 = np.percentile(sorted_latency, 99)
+x_max = np.percentile(sorted_latency, 99.5)
 
 # Plot
-fig = go.Figure(
+fig = go.Figure()
+
+# ECDF line
+fig.add_trace(
     go.Scatter(
-        x=sorted_times,
+        x=sorted_latency,
         y=cumulative_proportion,
         mode="lines",
-        line={"color": BRAND, "width": 3.5, "shape": "hv"},
-        hovertemplate=("<b>Finish Time</b>: %{x:.1f} min<br><b>Cumulative</b>: %{y:.1%}<br><extra></extra>"),
+        line={"color": BRAND, "width": 2.5, "shape": "hv"},
+        hovertemplate="<b>Latency</b>: %{x:.1f} ms<br><b>Cumulative</b>: %{y:.1%}<extra></extra>",
         showlegend=False,
     )
 )
 
+# Percentile reference lines (dashed horizontal)
+for pct_val, pct_label, y_pct in [(p50, "P50", 0.50), (p90, "P90", 0.90), (p99, "P99", 0.99)]:
+    fig.add_shape(
+        type="line",
+        x0=0,
+        x1=pct_val,
+        y0=y_pct,
+        y1=y_pct,
+        line={"color": INK_SOFT, "width": 1, "dash": "dot"},
+        layer="below",
+    )
+    fig.add_shape(
+        type="line",
+        x0=pct_val,
+        x1=pct_val,
+        y0=0,
+        y1=y_pct,
+        line={"color": INK_SOFT, "width": 1, "dash": "dot"},
+        layer="below",
+    )
+    fig.add_annotation(
+        x=pct_val,
+        y=y_pct,
+        text=f"<b>{pct_label}</b> {pct_val:.0f} ms",
+        showarrow=False,
+        xanchor="left",
+        yanchor="bottom",
+        xshift=6,
+        yshift=4,
+        font={"size": 10, "color": INK_SOFT},
+    )
+
 # Style
+title_text = "HTTP API Latency · ecdf-basic · python · plotly · anyplot.ai"
 fig.update_layout(
-    title={
-        "text": "Marathon Finishing Times · ecdf-basic · plotly · anyplot.ai",
-        "font": {"size": 28, "color": INK},
-        "x": 0.5,
-        "xanchor": "center",
-        "y": 0.95,
-    },
+    autosize=False,
+    title={"text": title_text, "font": {"size": 16, "color": INK}, "x": 0.5, "xanchor": "center", "y": 0.95},
     xaxis={
-        "title": {"text": "Finishing Time (minutes)", "font": {"size": 22, "color": INK}, "standoff": 12},
-        "tickfont": {"size": 18, "color": INK_SOFT},
+        "title": {"text": "Response Time (ms)", "font": {"size": 12, "color": INK}, "standoff": 12},
+        "tickfont": {"size": 10, "color": INK_SOFT},
         "gridcolor": GRID,
         "gridwidth": 1,
         "linecolor": INK_SOFT,
         "zeroline": False,
-        "showline": True,
+        "showline": False,
         "mirror": False,
-        "ticksuffix": " min",
+        "range": [0, x_max],
     },
     yaxis={
-        "title": {"text": "Cumulative Proportion of Runners", "font": {"size": 22, "color": INK}, "standoff": 12},
-        "tickfont": {"size": 18, "color": INK_SOFT},
+        "title": {"text": "Cumulative Proportion of Requests", "font": {"size": 12, "color": INK}, "standoff": 12},
+        "tickfont": {"size": 10, "color": INK_SOFT},
         "gridcolor": GRID,
         "gridwidth": 1,
         "linecolor": INK_SOFT,
         "zeroline": False,
-        "showline": True,
+        "showline": False,
         "mirror": False,
         "range": [0, 1.02],
         "tickformat": ".0%",
@@ -76,13 +121,13 @@
     paper_bgcolor=PAGE_BG,
     plot_bgcolor=PAGE_BG,
     font={"color": INK, "family": "Inter, Helvetica Neue, Arial, sans-serif"},
-    margin={"l": 110, "r": 70, "t": 110, "b": 90},
+    margin={"l": 80, "r": 40, "t": 80, "b": 60},
     hovermode="x unified",
-    hoverlabel={"bgcolor": ELEVATED_BG, "bordercolor": INK_SOFT, "font": {"color": INK, "size": 15}, "align": "left"},
+    hoverlabel={"bgcolor": ELEVATED_BG, "bordercolor": INK_SOFT, "font": {"color": INK, "size": 12}, "align": "left"},
 )
 
 # Save
-fig.write_image(f"plot-{THEME}.png", width=1600, height=900, scale=3)
+fig.write_image(f"plot-{THEME}.png", width=800, height=450, scale=4)
 fig.write_html(
     f"plot-{THEME}.html",
     include_plotlyjs="cdn",