Initial scaffold: Flask webui + APScheduler + Playwright automation for MassPrice rule scheduling

Drives massprice.tcgplayer.com's Run Rule action per-rule on a
user-configured schedule (multiple times/day, day-of-week toggles),
replacing MassPrice's native scheduler (capped at 15 schedules
account-wide, one run/day, with observed clock drift). Deployed via
Forgejo push-to-deploy on Unraid, matching arr-summary/card-grader.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H6TgffxTvYhqxykAbVQg2v

templates/login.html

@@ -0,0 +1,13 @@
+{% extends "_shell.html" %}
+{% block title %}Log In · MassPrice Scheduler{% endblock %}
+{% block content %}
+<div class="login-card">
+  <h1>MassPrice Scheduler</h1>
+  {% if error %}<p class="error">{{ error }}</p>{% endif %}
+  <form method="post">
+    <label for="password">Password</label>
+    <input type="password" id="password" name="password" autofocus required>
+    <button type="submit" class="btn btn-primary">Log In</button>
+  </form>
+</div>
+{% endblock %}