Initial commit: LMS microservices scaffold

- Gradle multi-module: libs/{common-http,security-jwt,markdown,test-support},
  services/{identity,academic,progress,gateway}, web (Thymeleaf+htmx)
- identity-service: JWT auth (RSA), accounts, students, groups, enrollment,
  import from XLSX/CSV, credentials export, password reset
- academic-service: lab import from JSON/zip (markdown + YAML + variants),
  levels, API
- progress-service: schema for student levels and variant assignments
- gateway: Spring Cloud Gateway, JWT validation, route propagation
- web: Server-side UI with flex/footer layout, light/dark theme toggle,
  admin dashboard, groups CRUD, student portal placeholder
- docker-compose: PostgreSQL 18
- Tests: identity smoke test with Testcontainers

libs/markdown/src/main/kotlin/ru/ysu/lms/markdown/LmsMarkdownAutoConfiguration.kt

@@ -0,0 +1,16 @@
+package ru.ysu.lms.markdown
+
+import org.springframework.boot.autoconfigure.AutoConfiguration
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
+import org.springframework.boot.context.properties.EnableConfigurationProperties
+import org.springframework.context.annotation.Bean
+
+@AutoConfiguration
+@EnableConfigurationProperties(MarkdownProperties::class)
+class LmsMarkdownAutoConfiguration {
+
+    @Bean
+    @ConditionalOnMissingBean
+    fun markdownRenderer(properties: MarkdownProperties): MarkdownRenderer =
+        MarkdownRenderer(allowHtml = properties.allowHtml)
+}

libs/markdown/src/main/kotlin/ru/ysu/lms/markdown/MarkdownProperties.kt

@@ -0,0 +1,9 @@
+package ru.ysu.lms.markdown
+
+import org.springframework.boot.context.properties.ConfigurationProperties
+
+@ConfigurationProperties(prefix = "lms.markdown")
+data class MarkdownProperties(
+    /** When true, raw HTML in the source markdown is passed through (still sanitized). */
+    val allowHtml: Boolean = false,
+)

libs/markdown/src/main/kotlin/ru/ysu/lms/markdown/MarkdownRenderer.kt

@@ -0,0 +1,113 @@
+package ru.ysu.lms.markdown
+
+import com.vladsch.flexmark.ext.autolink.AutolinkExtension
+import com.vladsch.flexmark.ext.footnotes.FootnoteExtension
+import com.vladsch.flexmark.ext.gfm.strikethrough.StrikethroughExtension
+import com.vladsch.flexmark.ext.gfm.tasklist.TaskListExtension
+import com.vladsch.flexmark.ext.tables.TablesExtension
+import com.vladsch.flexmark.html.HtmlRenderer
+import com.vladsch.flexmark.parser.Parser
+import com.vladsch.flexmark.util.data.MutableDataSet
+import org.owasp.html.HtmlPolicyBuilder
+import org.owasp.html.PolicyFactory
+
+/**
+ * Renders LMS markdown to sanitized HTML.
+ *
+ * Supported beyond CommonMark: tables, strikethrough, task lists, footnotes,
+ * autolinks and the custom spoiler container:
+ *
+ * ```
+ * :::spoiler Заголовок
+ * скрытый текст (тоже markdown)
+ * :::
+ * ```
+ *
+ * The result is always passed through an allow-list HTML sanitizer, so authors
+ * cannot inject scripts or arbitrary markup.
+ */
+class MarkdownRenderer(
+    private val allowHtml: Boolean = false,
+) {
+    private val options = MutableDataSet().apply {
+        set(
+            Parser.EXTENSIONS,
+            listOf(
+                TablesExtension.create(),
+                StrikethroughExtension.create(),
+                TaskListExtension.create(),
+                FootnoteExtension.create(),
+                AutolinkExtension.create(),
+            ),
+        )
+        set(HtmlRenderer.GENERATE_HEADER_ID, true)
+        set(HtmlRenderer.SOFT_BREAK, "<br />\n")
+        set(HtmlRenderer.ESCAPE_HTML, !allowHtml)
+    }
+
+    private val parser: Parser = Parser.builder(options).build()
+    private val renderer: HtmlRenderer = HtmlRenderer.builder(options).build()
+    private val sanitizer: PolicyFactory = buildSanitizer()
+
+    fun render(markdown: String): String = sanitizer.sanitize(renderRaw(markdown, depth = 0))
+
+    private fun renderRaw(markdown: String, depth: Int): String {
+        val out = StringBuilder()
+        var cursor = 0
+        for (match in SPOILER.findAll(markdown)) {
+            out.append(renderSegment(markdown.substring(cursor, match.range.first)))
+            val title = match.groupValues[1].trim().ifBlank { "Спойлер" }
+            val body = match.groupValues[2]
+            val inner = if (depth < MAX_DEPTH) {
+                renderRaw(body, depth + 1)
+            } else {
+                renderSegment(body)
+            }
+            out.append("<details class=\"spoiler\"><summary>")
+            out.append(escapeHtml(title))
+            out.append("</summary><div class=\"spoiler-body\">")
+            out.append(inner)
+            out.append("</div></details>")
+            cursor = match.range.last + 1
+        }
+        out.append(renderSegment(markdown.substring(cursor)))
+        return out.toString()
+    }
+
+    private fun renderSegment(markdown: String): String =
+        renderer.render(parser.parse(markdown))
+
+    private fun escapeHtml(value: String): String = value
+        .replace("&", "&amp;")
+        .replace("<", "&lt;")
+        .replace(">", "&gt;")
+        .replace("\"", "&quot;")
+
+    private fun buildSanitizer(): PolicyFactory = HtmlPolicyBuilder()
+        .allowElements(
+            "p", "br", "hr",
+            "h1", "h2", "h3", "h4", "h5", "h6",
+            "strong", "b", "em", "i", "del", "s", "blockquote",
+            "ul", "ol", "li",
+            "a", "img",
+            "code", "pre",
+            "table", "thead", "tbody", "tr", "th", "td",
+            "details", "summary", "div", "span", "sup", "sub", "kbd", "figure", "figcaption",
+        )
+        .allowAttributes("href").onElements("a")
+        .allowAttributes("title").onElements("a", "img")
+        .allowAttributes("src", "alt").onElements("img")
+        .allowAttributes("class").onElements("code", "pre", "div", "span", "details", "summary", "table", "th", "td")
+        .allowAttributes("id").onElements("h1", "h2", "h3", "h4", "h5", "h6")
+        .allowAttributes("colspan", "rowspan").onElements("td", "th")
+        .allowUrlProtocols("http", "https", "mailto")
+        .requireRelNofollowOnLinks()
+        .toFactory()
+
+    private companion object {
+        const val MAX_DEPTH = 5
+        val SPOILER = Regex(
+            pattern = "(?ms)^[ \\t]*:::[ \\t]*spoiler(?:[ \\t]+(.+?))?[ \\t]*\\r?\\n(.*?)^[ \\t]*:::[ \\t]*$",
+        )
+    }
+}

libs/markdown/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -0,0 +1 @@
+ru.ysu.lms.markdown.LmsMarkdownAutoConfiguration