feat(bokeh): implement line-filled (#6486)

## Implementation: `line-filled` - python/bokeh

Implements the **python/bokeh** version of `line-filled`.

**File:** `plots/line-filled/implementations/python/bokeh.py`

**Parent Issue:** #2643

---
:robot: *[impl-generate
workflow](https://github.com/MarkusNeusinger/anyplot/actions/runs/25749578526)*

---------

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-filled/implementations/python/bokeh.py

@@ -1,15 +1,28 @@
-""" pyplots.ai
+""" anyplot.ai
 line-filled: Filled Line Plot
-Library: bokeh 3.8.1 | Python 3.13.11
-Quality: 91/100 | Created: 2025-12-30
+Library: bokeh 3.9.0 | Python 3.13.13
+Quality: 91/100 | Updated: 2026-05-12
 """
 
+import os
+import time
+from pathlib import Path
+
 import numpy as np
-from bokeh.io import export_png, save
+from bokeh.io import output_file, save
 from bokeh.models import ColumnDataSource, HoverTool
 from bokeh.plotting import figure
-from bokeh.resources import CDN
+from selenium import webdriver
+from selenium.webdriver.chrome.options import Options
+
 
+# 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"
+BRAND = "#009E73"
 
 # Data - Monthly website traffic over a year
 np.random.seed(42)
@@ -29,19 +42,19 @@
 p = figure(
     width=4800,
     height=2700,
-    title="line-filled · bokeh · pyplots.ai",
+    title="line-filled · bokeh · anyplot.ai",
     x_axis_label="Month",
-    y_axis_label="Website Visitors",
+    y_axis_label="Website Visitors (count)",
 )
 
 # Filled area using varea
-p.varea(x="month", y1="traffic_zero", y2="traffic", source=source, fill_color="#306998", fill_alpha=0.4)
+p.varea(x="month", y1="traffic_zero", y2="traffic", source=source, fill_color=BRAND, fill_alpha=0.35)
 
 # Line on top of the fill
-p.line(x="month", y="traffic", source=source, line_color="#306998", line_width=4)
+p.line(x="month", y="traffic", source=source, line_color=BRAND, line_width=4)
 
 # Add points for visual emphasis
-p.scatter(x="month", y="traffic", source=source, size=12, color="#306998", fill_alpha=0.8)
+p.scatter(x="month", y="traffic", source=source, size=12, color=BRAND, fill_alpha=0.8)
 
 # Add hover tool
 hover = HoverTool(tooltips=[("Month", "@month"), ("Visitors", "@traffic{0,0}")])
@@ -54,21 +67,53 @@
 p.xaxis.major_label_text_font_size = "18pt"
 p.yaxis.major_label_text_font_size = "18pt"
 
+# Theme-adaptive text colors
+p.title.text_color = INK
+p.xaxis.axis_label_text_color = INK
+p.yaxis.axis_label_text_color = INK
+p.xaxis.major_label_text_color = INK_SOFT
+p.yaxis.major_label_text_color = INK_SOFT
+
 # Grid styling
-p.xgrid.grid_line_alpha = 0.3
-p.ygrid.grid_line_alpha = 0.3
-p.xgrid.grid_line_dash = [6, 4]
-p.ygrid.grid_line_dash = [6, 4]
+p.xgrid.grid_line_alpha = 0.10
+p.ygrid.grid_line_alpha = 0.10
+p.xgrid.grid_line_color = INK
+p.ygrid.grid_line_color = INK
+
+# Axis styling
+p.xaxis.axis_line_color = INK_SOFT
+p.yaxis.axis_line_color = INK_SOFT
+p.xaxis.major_tick_line_color = INK_SOFT
+p.yaxis.major_tick_line_color = INK_SOFT
 
 # Background
-p.background_fill_color = "#fafafa"
-p.border_fill_color = "#ffffff"
+p.background_fill_color = PAGE_BG
+p.border_fill_color = PAGE_BG
+p.outline_line_color = INK_SOFT
 
 # X-axis ticks for each month
 p.xaxis.ticker = list(range(1, 13))
 
-# Save as PNG and HTML
-export_png(p, filename="plot.png")
+# Save as interactive HTML
+output_file(f"plot-{THEME}.html")
+save(p)
+
+# Screenshot with headless Chrome
+W, H = 4800, 2700
+opts = Options()
+for arg in (
+    "--headless=new",
+    "--no-sandbox",
+    "--disable-dev-shm-usage",
+    "--disable-gpu",
+    f"--window-size={W},{H}",
+    "--hide-scrollbars",
+):
+    opts.add_argument(arg)
 
-# Also save interactive HTML
-save(p, filename="plot.html", resources=CDN, title="line-filled · bokeh · pyplots.ai")
+driver = webdriver.Chrome(options=opts)
+driver.set_window_size(W, H)
+driver.get(f"file://{Path(f'plot-{THEME}.html').resolve()}")
+time.sleep(3)  # Let bokeh's JS render the canvas
+driver.save_screenshot(f"plot-{THEME}.png")
+driver.quit()