Pointer in the editor; new screenshots and an editor section in the README

Scenes for the screenshots come from export_scenes (src/scenes.rs) and are
taken with tools/screenshots.py in the Playwright image.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/screenshots.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+"""Screenshots for docs/screenshots.
+
+1. `cargo test --release export_scenes -- --ignored` writes the scene savegames to /tmp/scenes.
+2. Build the WASM file and serve www/ with it and mq_js_bundle.js on http://127.0.0.1:18190/
+   (no savegame service, so no login).
+3. Copy /tmp/scenes/*.json next to this script into a folder mounted as /shots and run it in the
+   Playwright image with host networking, e.g.
+   docker run --rm --network host -v /tmp/shots:/shots mcr.microsoft.com/playwright/python:v1.62.0-noble \
+     bash -c "pip install playwright==1.62.0 --break-system-packages; python3 /shots/screenshots.py"
+   The pictures land in /shots/out (1280x800, English).
+"""
+import json, glob, os
+from playwright.sync_api import sync_playwright
+URL = 'http://127.0.0.1:18190/'
+ARGS = ['--use-gl=angle', '--use-angle=swiftshader', '--enable-unsafe-swiftshader', '--ignore-gpu-blocklist']
+def page_with(p, store):
+    b = p.chromium.launch(args=ARGS)
+    page = b.new_page(viewport={'width': 1280, 'height': 800})
+    page.goto(URL)
+    page.evaluate("(s) => { for (const k in s) localStorage.setItem(k, s[k]); }", store)
+    page.reload()
+    page.wait_for_timeout(13000)
+    return b, page
+def steps(page, st):
+    for s in st:
+        if 'click' in s: page.mouse.click(*s['click'])
+        if 'move' in s: page.mouse.move(*s['move'])
+        if 'key' in s: page.keyboard.press(s['key'])
+        page.wait_for_timeout(s.get('wait', 1500))
+        if 'shot' in s: page.screenshot(path='/shots/out/' + s['shot'] + '.png')
+os.makedirs('/shots/out', exist_ok=True)
+with sync_playwright() as p:
+    # title and bestiary
+    b, page = page_with(p, {'dc.lang': 'en'})
+    page.mouse.move(1270, 790); page.wait_for_timeout(500)
+    page.screenshot(path='/shots/out/title-battle.png')
+    b.close()
+    # scenes from savegames: Continue on the title screen
+    for f in sorted(glob.glob('/shots/*.json')):
+        name = os.path.basename(f)[:-5]
+        b, page = page_with(p, {'dc.lang': 'en', 'dc.autosave': open(f).read()})
+        steps(page, [{'click': [635, 207], 'wait': 6000}, {'move': [700, 160], 'wait': 3000, 'shot': name}])
+        b.close()
+    # the editors (English button positions)
+    b, page = page_with(p, {'dc.lang': 'en'})
+    steps(page, [
+        {'click': [635, 255], 'wait': 2000}, {'click': [840, 20], 'wait': 1500},
+        {'click': [840, 172], 'wait': 3000}, {'move': [700, 420], 'wait': 800, 'shot': 'editor-campaign'},
+        {'click': [200, 200], 'wait': 1500}, {'click': [336, 61], 'wait': 1500}, {'move': [1000, 120], 'wait': 600, 'shot': 'editor-triggers'},
+        {'click': [750, 136], 'wait': 2000}, {'move': [900, 500], 'wait': 600, 'shot': 'editor-blocks'},
+        {'click': [70, 22], 'wait': 1500}, {'click': [246, 61], 'wait': 1200}, {'click': [200, 183], 'wait': 4000},
+        {'click': [250, 145], 'wait': 1500}, {'move': [1000, 600], 'wait': 800, 'shot': 'editor-map'},
+    ])
+    b.close()