Add Playwright capture script for README images

scripts/capture-screenshots.py

@@ -0,0 +1,90 @@
+"""Regenerates docs/img/* from base.html with Playwright (demo data only).
+
+Setup:  pip install playwright pillow && playwright install chromium
+Serve:  mkdir /tmp/wt && cd /tmp/wt && ln -s <repo> web_template && ln -s <repo>/base.html base.html \
+        && python3 -m http.server 8100
+Run:    python3 scripts/capture-screenshots.py
+"""
+import asyncio, io
+from PIL import Image
+from playwright.async_api import async_playwright
+import pathlib
+OUT=str(pathlib.Path(__file__).resolve().parent.parent/'docs'/'img')
+URL='http://127.0.0.1:8100/base.html'  # serve so that /web_template/base.css and /base.html both resolve
+TOP="document.activeElement&&document.activeElement.blur();document.documentElement.style.scrollBehavior='auto';window.scrollTo(0,0)"
+HIDE = "document.addEventListener('DOMContentLoaded',()=>{document.querySelectorAll('div').forEach(d=>{if(d.style.position==='fixed'&&d.style.bottom==='1rem'&&d.style.left==='1rem')d.style.display='none'})})"
+async def hdr(pg,text):
+    h=pg.locator('.lt-section-header', has_text=text).first
+    return h.locator('xpath=..') if await h.count() else None
+async def theme_run(theme):
+    async with async_playwright() as p:
+        b=await p.chromium.launch()
+        ctx=await b.new_context(viewport={'width':1440,'height':900})
+        await ctx.add_init_script(HIDE)
+        await ctx.add_init_script(f"try{{localStorage.setItem('lt_theme','{theme}')}}catch(e){{}}")
+        pg=await ctx.new_page(); await pg.goto(URL); await pg.wait_for_timeout(5000)
+        await pg.evaluate(TOP); await pg.wait_for_timeout(500)
+        await pg.screenshot(path=f'{OUT}/{theme}-dashboard.png', full_page=True, clip={'x':0,'y':0,'width':1440,'height':900})
+        if theme=='dark':
+            async def clipsec(text,name,extra=None,fixed=None):
+                h=pg.locator('.lt-section-header', has_text=text).first
+                if not await h.count(): print('missing',text); return
+                await h.scroll_into_view_if_needed()
+                hb=await h.bounding_box(); sy=await pg.evaluate('window.scrollY')
+                top=hb['y']+sy
+                if fixed: bot=top+fixed
+                else:
+                    body=h.locator('xpath=following-sibling::*[1]'); bb=await body.bounding_box(); bot=bb['y']+sy+bb['height']
+                await pg.screenshot(path=f'{OUT}/{name}.png', full_page=True, clip={'x':0,'y':top-4,'width':1440,'height':bot-top+8}); print('ok',name)
+            await pg.evaluate(TOP)
+            await clipsec('Ticket Queue','ticket-queue')
+            await clipsec('Component Reference','components',fixed=520)
+            await clipsec('Alert Banners','alerts')
+            await clipsec('SLA Banners','sla-banners')
+            await clipsec('Data Grid','data-grid')
+            await clipsec('Progress Bars','progress-bars')
+            await pg.evaluate(TOP); await pg.wait_for_timeout(300)
+            kb=pg.get_by_text('Kanban',exact=False).first
+            try:
+                await kb.click(timeout=3000); await pg.wait_for_timeout(900); await pg.evaluate(TOP); await pg.wait_for_timeout(500)
+                await pg.screenshot(path=f'{OUT}/kanban.png', full_page=True, clip={'x':0,'y':0,'width':1440,'height':900}); print('ok kanban')
+            except Exception as e: print('kanban fail',str(e)[:80])
+            await pg.evaluate(TOP); await pg.keyboard.press('Control+k'); await pg.wait_for_timeout(500)
+            await pg.keyboard.type('ti',delay=80); await pg.wait_for_timeout(500)
+            await pg.screenshot(path=f'{OUT}/command-palette.png', clip={'x':320,'y':60,'width':800,'height':420})
+        await b.close()
+async def gif():
+    frames=[]; 
+    async with async_playwright() as p:
+        b=await p.chromium.launch()
+        ctx=await b.new_context(viewport={'width':1280,'height':720})
+        await ctx.add_init_script(HIDE)
+        await ctx.add_init_script("try{localStorage.setItem('lt_theme','dark')}catch(e){}")
+        pg=await ctx.new_page(); await pg.goto(URL); await pg.wait_for_timeout(1200)
+        async def snap(n=1,ms=0):
+            if ms: await pg.wait_for_timeout(ms)
+            im=Image.open(io.BytesIO(await pg.screenshot())).convert('RGB').resize((960,540),Image.LANCZOS)
+            for _ in range(n): frames.append(im)
+        await snap(2,300)                       # boot sequence
+        await snap(2,1200); await snap(1,1500)
+        await pg.evaluate(TOP); await pg.wait_for_timeout(600); await snap(3)
+        await pg.keyboard.press('Control+k'); await snap(2,500)
+        for ch in 'new':
+            await pg.keyboard.type(ch); await snap(1,250)
+        await snap(3,300)
+        await pg.keyboard.press('Enter'); await snap(3,600)   # toast
+        await pg.wait_for_timeout(1500)
+        await pg.evaluate("lt.theme.set('light')"); await snap(3,600)
+        await pg.evaluate("lt.theme.set('dark')"); await snap(2,600)
+        l=await hdr(pg,'Component Reference')
+        if l:
+            await l.scroll_into_view_if_needed(); await snap(3,500)
+        for y in (500,1000,1500):
+            await pg.mouse.wheel(0,500); await snap(2,500)
+        await b.close()
+    pal=[f.quantize(colors=96,method=Image.MEDIANCUT,dither=Image.NONE) for f in frames]
+    pal[0].save(f'{OUT}/demo.gif',save_all=True,append_images=pal[1:],duration=450,loop=0,optimize=True)
+    print('gif frames',len(frames))
+async def main():
+    await theme_run('dark'); await theme_run('light'); await gif()
+asyncio.run(main())