feat: add videodb media index with Docker stack

- Add videodb PHP/MySQL media collection manager (Blu-ray, DVD, CD)
- Dockerfile: PHP 8.1 + Apache with GD/mysqli/exif extensions
- docker-compose.yml: app on port 6761 + MySQL 8.0 with health checks
- docker-entrypoint.sh: auto-generates config.inc.php from env vars,
  waits for MySQL, initializes DB schema idempotently
- init-db.php: CLI schema installer using app's own prefix_query() logic
- Persistent volumes for DB, cache, and cover images

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

videodb/templates/nexgen/login.tpl

@@ -0,0 +1,59 @@
+{*
+  Login template
+  $Id: login.tpl,v 1.3 2013/03/12 19:13:18 andig2 Exp $
+*}
+
+<!-- {$smarty.template} -->
+
+<div class="row">
+	<div class="small-12 large-4 columns small-centered panel">
+
+		{if $error}
+		<div class="alert-box">
+			{$error}
+			<a href="#" class="close">&times;</a>
+		</div>
+		{/if}
+
+		<p>{$lang.enterusername}</p>
+
+		<form action="login.php" method="post">
+			<input type="hidden" value="{$refer}" name="refer"/>
+
+			<div class="row">
+				<div class="small-4 columns">
+					<p>{$lang.username}:</p>
+				</div><!-- col -->
+
+				<div class="small-8 columns">
+					<input type="text" name="username" />
+				</div><!-- col -->
+			</div><!-- row -->
+
+			<div class="row">
+				<div class="small-4 columns">
+					<p>{$lang.password}:</p>
+				</div><!-- col -->
+
+				<div class="small-8 columns">
+					<input type="password" name="password" />
+				</div><!-- col -->
+			</div><!-- row -->
+
+			<div class="row">
+				<div class="small-12 columns">
+					<p>
+						<label class="inline"><input type="checkbox" name="permanent" value="1" />{$lang.stayloggedin}</label>
+					</p>
+				</div><!-- col -->
+			</div><!-- row -->
+
+			<div class="row">
+				<div class="small-12 columns small-centered">
+					<input type="submit" class="button" value="{$lang.login}" />
+				</div><!-- col -->
+			</div><!-- row -->
+		</form>
+
+	</div><!-- col -->
+</div><!-- row -->