feat(server): Routen, Seiten und Artefakte tragen das Repository — /repos/<name>/… (Sitzung D)

Zweite Hälfte von Sitzung D (docs/plan/22-multi-repo.md, PR #13): Der Server
bediente bisher genau ein Repository der Registry. Jede Route — API, Seiten,
Artefakt-Dateien — arbeitete auf `registry.current()`; ein zweites
registriertes Repository wurde gebaut und gepollt, war aber unsichtbar und
unerreichbar.

Jeder Controller löst sein Repository jetzt je Anfrage auf, statt das
bediente als Bohne zu halten; jede Route ist zweimal gemappt. Die unscoped
Form ist kein Übergangs-Alias, sondern dauerhaft die Art zu sagen „das
bediente Repository" — Lesezeichen und die nach Gitea geposteten Links
kennen kein Segment.

Entschieden gegen die Repo-Spalte: Die Seiten bleiben je Repository, die
Navigation bekommt einen Umschalter. Die Aktionen einer Zeile brauchen das
Repository ohnehin, Branches kommen von einem origin und Artefakte aus einem
Store — und bei dem einen Repository, das die meisten Installationen haben,
wäre eine Spalte nur Rauschen.

Das Link-Präfix folgt der ZAHL der bedienten Repositories, nicht dem Weg, über
den eine Seite erreicht wurde: mit einem behält die Installation ihre
bisherigen URLs (Abnahmekriterium der Sitzung), mit mehreren benennt jeder
Link sein Repository. werkator.js liest das Präfix einmal aus einem
`werkator-repo-base`-Meta. `BranchPermalinks.permanentUrl` bekommt es
ebenfalls — der permanente Schlüssel ist ein Hash des Build-Namens allein,
zwei Repositories mit `main` teilten sich sonst eine permanente URL.

Fünf neue Tests, Gegenprobe per Mutation gezogen (Präfix fest auf leer →
genau der Mehr-Repo-Test fällt). 498 Tests grün, ktlint sauber. PR-Dokument
docs/prs/2026-09-03-PR#13-…, Plan, Architektur-Skill und AGENTS.md
nachgezogen.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/main/resources/static/werkator.js

@@ -99,6 +99,17 @@ function metaContent(name) {
 
 const giteaRepoUrl = metaContent("werkator-gitea-repo-url");
 
+// Empty with one served repository, `/repos/<name>` with several (ADR 0009). Every
+// path this script builds itself is prefixed with it, so an action triggered on a
+// repository's page acts on that repository — the paths rendered into the DOM
+// (`data-api`, artifact links) already carry it.
+const repoBase = metaContent("werkator-repo-base") || "";
+
+/** The API of the repository this page belongs to; `/api` when only one is served. */
+function apiBase() {
+    return repoBase ? "/api" + repoBase : "/api";
+}
+
 // The control token is deliberately NOT embedded in the pages: reading them is
 // unauthenticated, so anyone could have read it out of the HTML. The operator
 // pastes it once per browser from `.git/werkator/control-token` on the server;
@@ -389,7 +400,7 @@ function renderBuildRow(build, allowRestart, restartAtOriginHead) {
     const inProgress = build.status === "running" || build.status === "pending";
     if (build.artifactKey) {
         const artifactLink = elem("a", "artifact-link", inProgress ? "⏳" : "📄");
-        artifactLink.href = "/builds/" + encodeURIComponent(build.artifactKey);
+        artifactLink.href = repoBase + "/builds/" + encodeURIComponent(build.artifactKey);
         artifactLink.title = inProgress ? "Open build log — no artifacts yet" : "Open artifacts";
         artifactsCell.appendChild(artifactLink);
     }
@@ -542,7 +553,7 @@ function initCurrentBuilds() {
             return;
         }
         const offset = logOffsets.get(build.artifactKey) || 0;
-        const url = `/api/builds/current/${encodeURIComponent(build.artifactKey)}/log?offset=${offset}`;
+        const url = `${apiBase()}/builds/current/${encodeURIComponent(build.artifactKey)}/log?offset=${offset}`;
         const tail = await fetchJson(url);
         logOffsets.set(build.artifactKey, tail.nextOffset);
         if (tail.content) {
@@ -690,11 +701,11 @@ document.addEventListener("click", async (event) => {
     try {
         if (action === "restart") {
             const atOriginHead = button.dataset.atOriginHead === "true" ? "&atOriginHead=true" : "";
-            await sendAction("/api/builds/restart?branch=" + encodeURIComponent(button.dataset.branch) + atOriginHead, "POST");
+            await sendAction(apiBase() + "/builds/restart?branch=" + encodeURIComponent(button.dataset.branch) + atOriginHead, "POST");
         } else if (action === "cancel") {
-            await sendAction(`/api/builds/${encodeURIComponent(button.dataset.artifactKey)}/cancel`, "POST");
+            await sendAction(`${apiBase()}/builds/${encodeURIComponent(button.dataset.artifactKey)}/cancel`, "POST");
         } else if (action === "delete") {
-            await sendAction("/api/builds/" + encodeURIComponent(button.dataset.artifactKey), "DELETE");
+            await sendAction(apiBase() + "/builds/" + encodeURIComponent(button.dataset.artifactKey), "DELETE");
         }
         if (refreshNow) {
             refreshNow();

src/main/resources/templates/builds.html

@@ -52,13 +52,13 @@
                 <td class="duration-cell" data-label="Duration" th:text="${row.duration}">1:23</td>
                 <td data-label="Artifacts">
                     <a th:if="${row.artifactKey != ''}" class="artifact-link"
-                       th:href="'/builds/' + ${row.artifactKey}"
+                       th:href="${repoBase} + '/builds/' + ${row.artifactKey}"
                        th:text="${row.inProgress} ? '⏳' : '📄'"
                        th:title="${row.inProgress} ? 'Open build log — no artifacts yet' : 'Open artifacts'">📄</a>
                     <a th:if="${row.latestGreenUrl != null}" class="artifact-link"
                        th:href="${row.latestGreenUrl}"
                        title="Permanent link: artifacts of the latest green build">🔗</a>
-                    <a th:if="${row.inProgress}" class="artifact-link" href="/current"
+                    <a th:if="${row.inProgress}" class="artifact-link" th:href="${repoBase} + '/current'" href="/current"
                        title="Watch this build live">📡</a>
                     <span th:if="${row.artifactKey == ''}">n/a</span>
                 </td>

src/main/resources/templates/current.html

@@ -5,7 +5,7 @@
 <main>
     <h1 th:replace="~{fragments :: header(${pageTitle})}"></h1>
     <div th:replace="~{fragments :: nav(${view})}"></div>
-    <div id="current-builds" data-api="/api/builds/current">
+    <div id="current-builds" th:attr="data-api=${apiBase} + '/builds/current'" data-api="/api/builds/current">
         <p id="no-current" class="empty-panel" th:style="${#lists.isEmpty(currentBuilds)} ? '' : 'display: none'">
             No build is currently running.
         </p>

src/main/resources/templates/fragments.html

@@ -7,11 +7,14 @@
     <link rel="icon" href="/favicon.svg" type="image/svg+xml">
     <link rel="stylesheet" href="/werkator.css">
     <meta name="werkator-gitea-repo-url" th:content="${giteaRepoUrl}">
+    <!-- Empty with one served repository, `/repos/<name>` with several: werkator.js
+         builds its action and artifact URLs from it, so a page stays in its repository. -->
+    <meta name="werkator-repo-base" th:content="${repoBase}">
 </head>
 <body>
 
 <h1 th:fragment="header(title)">
-    <a class="title-home" href="/" aria-label="Open latest builds"><img src="/favicon.svg" alt=""></a>
+    <a class="title-home" th:href="${homeUrl}" href="/" aria-label="Open latest builds"><img src="/favicon.svg" alt=""></a>
     <span class="title-text" th:text="${title}">Latest Builds</span>
     <span class="repo-name" th:unless="${#strings.isEmpty(repoName)}" th:text="${repoName}">owner/repo</span>
 </h1>
@@ -20,15 +23,23 @@
 <div class="view-row">
     <nav class="view-toggle">
         <span th:if="${view == 'latest'}">Latest</span>
-        <a th:unless="${view == 'latest'}" href="/">Latest</a>
+        <a th:unless="${view == 'latest'}" th:href="${homeUrl}" href="/">Latest</a>
         <span th:if="${view == 'branches'}">Branches</span>
-        <a th:unless="${view == 'branches'}" href="/branches">Branches</a>
+        <a th:unless="${view == 'branches'}" th:href="${repoBase} + '/branches'" href="/branches">Branches</a>
         <span th:if="${view == 'history'}">History</span>
-        <a th:unless="${view == 'history'}" href="/history">History</a>
+        <a th:unless="${view == 'history'}" th:href="${repoBase} + '/history'" href="/history">History</a>
         <span th:if="${view == 'current'}">Current</span>
         <span th:if="${view == 'system'}">System</span>
         <a th:unless="${view == 'system'}" href="/system">System</a>
     </nav>
+    <!-- The repository switcher (ADR 0009): what makes several repositories one UI.
+         With a single served repository there is nothing to switch, and the block is absent. -->
+    <nav class="repo-switch" th:if="${multiRepo}">
+        <th:block th:each="r : ${repos}">
+            <span th:if="${r.current}" th:text="${r.name}" class="repo-current">werkator</span>
+            <a th:unless="${r.current}" th:href="${r.url}" th:text="${r.name}">other</a>
+        </th:block>
+    </nav>
     <span class="view-row-actions">
         <span id="live-indicator" class="status status-unknown" title="live-update state">static</span>
         <button id="reload-button" class="reload-button" type="button" title="Reload view" aria-label="Reload view">⟳</button>