feat(plotly): implement line-timeseries (#6117)

## Implementation: `line-timeseries` - python/plotly

Implements the **python/plotly** version of `line-timeseries`.

**File:** `plots/line-timeseries/implementations/python/plotly.py`

**Parent Issue:** #2006

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/25590297718)*

---------

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/line-timeseries/implementations/python/plotly.py

@@ -1,72 +1,87 @@
-""" pyplots.ai
+""" anyplot.ai
 line-timeseries: Time Series Line Plot
-Library: plotly 6.5.0 | Python 3.13.11
-Quality: 92/100 | Created: 2025-12-26
+Library: plotly 6.7.0 | Python 3.13.13
+Quality: 90/100 | Updated: 2026-05-09
 """
 
+import os
+
 import numpy as np
 import pandas as pd
 import plotly.graph_objects as go
 
 
-# Data - Daily temperature readings over one year
+# Theme tokens
+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
+
+# Data - Stock prices with uptrend
 np.random.seed(42)
 dates = pd.date_range(start="2024-01-01", end="2024-12-31", freq="D")
+days = np.arange(len(dates))
+trend = 100 + 0.15 * days
+volatility = 5 * np.sin(2 * np.pi * days / 60)
+noise = np.random.randn(len(dates)) * 2
+prices = trend + volatility + noise
 
-# Create realistic temperature pattern with seasonal variation
-day_of_year = np.arange(len(dates))
-seasonal = 15 * np.sin(2 * np.pi * (day_of_year - 80) / 365)  # Peak around late July
-baseline = 12  # Average temperature
-noise = np.random.randn(len(dates)) * 3
-temperatures = baseline + seasonal + noise
-
-df = pd.DataFrame({"date": dates, "temperature": temperatures})
+df = pd.DataFrame({"date": dates, "price": prices})
 
 # Create plot
 fig = go.Figure()
 
 fig.add_trace(
     go.Scatter(
         x=df["date"],
-        y=df["temperature"],
+        y=df["price"],
         mode="lines",
-        line={"color": "#306998", "width": 2.5},
-        name="Temperature",
-        hovertemplate="Date: %{x|%b %d, %Y}<br>Temperature: %{y:.1f}°C<extra></extra>",
+        line={"color": BRAND, "width": 3},
+        name="Stock Price",
+        hovertemplate="Date: %{x|%b %d, %Y}<br>Price: $%{y:.2f}<extra></extra>",
     )
 )
 
 # Layout for 4800x2700 px
 fig.update_layout(
     title={
-        "text": "Daily Temperature 2024 · line-timeseries · plotly · pyplots.ai",
-        "font": {"size": 32},
+        "text": "line-timeseries · plotly · anyplot.ai",
+        "font": {"size": 28, "color": INK},
         "x": 0.5,
         "xanchor": "center",
     },
     xaxis={
-        "title": {"text": "Date", "font": {"size": 24}},
-        "tickfont": {"size": 18},
+        "title": {"text": "Date", "font": {"size": 22, "color": INK}},
+        "tickfont": {"size": 18, "color": INK_SOFT},
         "tickformat": "%b %Y",
         "dtick": "M1",
-        "gridcolor": "rgba(128, 128, 128, 0.3)",
+        "gridcolor": GRID,
         "gridwidth": 1,
         "showgrid": True,
+        "linecolor": INK_SOFT,
+        "zerolinecolor": INK_SOFT,
+        "rangeslider": {"visible": True, "thickness": 0.05},
     },
     yaxis={
-        "title": {"text": "Temperature (°C)", "font": {"size": 24}},
-        "tickfont": {"size": 18},
-        "gridcolor": "rgba(128, 128, 128, 0.3)",
+        "title": {"text": "Stock Price ($)", "font": {"size": 22, "color": INK}},
+        "tickfont": {"size": 18, "color": INK_SOFT},
+        "gridcolor": GRID,
         "gridwidth": 1,
         "showgrid": True,
+        "linecolor": INK_SOFT,
+        "zerolinecolor": INK_SOFT,
     },
-    template="plotly_white",
-    plot_bgcolor="white",
-    paper_bgcolor="white",
+    paper_bgcolor=PAGE_BG,
+    plot_bgcolor=PAGE_BG,
+    font={"color": INK},
     margin={"l": 100, "r": 80, "t": 120, "b": 100},
     showlegend=False,
+    hovermode="x unified",
 )
 
 # Save as PNG (4800x2700 px) and HTML
-fig.write_image("plot.png", width=1600, height=900, scale=3)
-fig.write_html("plot.html", include_plotlyjs="cdn")
+fig.write_image(f"plot-{THEME}.png", width=1600, height=900, scale=3)
+fig.write_html(f"plot-{THEME}.html", include_plotlyjs="cdn")