fix(themes): require a newer version for each publish

Compare the proposed version with the version currently published in the workshop before opening the publish dialog and again before upload. Reject invalid semver, duplicate versions, and downgrades, while tracking the just-submitted version in-session so pending updates cannot be published twice.

src/lib/components/theme/ThemeEditorWindow.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
   import Logo from '$assets/logo.png';
-  import { publishThemeToWorkshop } from '$lib/communityThemes';
+  import { fetchCommunityThemeDetails, publishThemeToWorkshop } from '$lib/communityThemes';
   import FontPreview from '$lib/components/theme/FontPreview.svelte';
   import ThemeBehaviorInspector from '$lib/components/theme/ThemeBehaviorInspector.svelte';
   import ThemeElementInspector from '$lib/components/theme/ThemeElementInspector.svelte';
@@ -173,6 +173,7 @@
   import { getCurrentWindow } from '@tauri-apps/api/window';
   import { open, save as saveDialog } from '@tauri-apps/plugin-dialog';
   import * as fs from '@tauri-apps/plugin-fs';
+  import semver from 'semver';
   import { sileo } from 'sileo';
   import { onMount, tick } from 'svelte';
   import { SvelteMap, SvelteSet } from 'svelte/reactivity';
@@ -287,6 +288,7 @@
   let panStart = { x: 0, y: 0, panX: 0, panY: 0 };
   const canvasScale = $derived(canvasFitScale * canvasZoom);
   let statusMessage = $state('Ready');
+  let lastPublishedVersion = $state<string | undefined>(undefined);
   let renamingId = $state<string | undefined>(undefined);
   let draggingLayer = $state<LayerDragItem | undefined>(undefined);
   let dropTarget = $state<LayerDropTarget | undefined>(undefined);
@@ -1803,6 +1805,7 @@
 
   async function loadContext() {
     loading = true;
+    lastPublishedVersion = undefined;
     try {
       const context = await invoke<ThemeEditorContext>('theme_editor_context');
       const parsed = context.themeJson
@@ -3340,6 +3343,63 @@
   let publishStatusMessage = $state('');
   let publishProgress = $state(0);
 
+  async function checkPublishVersion(): Promise<
+    { ok: true; version: string } | { ok: false; error: string }
+  > {
+    const proposed = semver.valid(definition.version.trim());
+    if (!proposed) {
+      return {
+        ok: false,
+        error: 'Use a semantic version such as 1.2.3 in the Theme tab before publishing.',
+      };
+    }
+
+    let publishedVersion = lastPublishedVersion;
+    const workshopId = definition.workshopId?.trim();
+    if (workshopId) {
+      let remoteVersion: string;
+      try {
+        remoteVersion = (await fetchCommunityThemeDetails(workshopId)).version?.trim() ?? '';
+      } catch (error) {
+        console.warn('[Workshop] Could not verify the published theme version:', error);
+        return {
+          ok: false,
+          error:
+            'Could not verify the current workshop version. Check your connection and try again.',
+        };
+      }
+
+      const validRemote = semver.valid(remoteVersion);
+      if (!validRemote) {
+        return {
+          ok: false,
+          error:
+            'The current workshop version could not be read. Contact a workshop administrator.',
+        };
+      }
+      if (!publishedVersion || semver.gt(validRemote, publishedVersion)) {
+        publishedVersion = validRemote;
+      }
+    }
+
+    if (publishedVersion) {
+      if (semver.eq(proposed, publishedVersion)) {
+        return {
+          ok: false,
+          error: `Version ${proposed} has already been published. Increase the version before publishing again.`,
+        };
+      }
+      if (!semver.gt(proposed, publishedVersion)) {
+        return {
+          ok: false,
+          error: `Version ${proposed} must be higher than the last published version ${publishedVersion}.`,
+        };
+      }
+    }
+
+    return { ok: true, version: proposed };
+  }
+
   async function openPublishDialog() {
     if (exporting || saving || publishing) return;
 
@@ -3362,10 +3422,21 @@
       return;
     }
 
+    const versionCheck = await checkPublishVersion();
+    if (!versionCheck.ok) {
+      sileo.error({
+        title: 'Version not publishable',
+        description: versionCheck.error,
+      });
+      return;
+    }
+    const versionChanged = definition.version !== versionCheck.version;
+    if (versionChanged) definition.version = versionCheck.version;
+
     const authorIdChanged = definition.authorId !== user.id;
     if (authorIdChanged) definition.authorId = user.id;
 
-    if (dirty || authorIdChanged) {
+    if (dirty || authorIdChanged || versionChanged) {
       const saved = await saveTheme({ notify: false });
       if (!saved) return;
     }
@@ -3404,17 +3475,34 @@
 
   async function handlePublishToWorkshop() {
     if (publishing) return;
-    if (!savedFolder) {
-      await saveTheme({ notify: false });
-      if (!savedFolder) return;
-    }
 
     const firstPublish = !definition.workshopId;
     publishing = true;
     publishProgress = 5;
-    publishStatusMessage = 'Packaging theme archive...';
+    publishStatusMessage = 'Checking version...';
 
     try {
+      const versionCheck = await checkPublishVersion();
+      if (!versionCheck.ok) {
+        sileo.error({
+          title: 'Version not publishable',
+          description: versionCheck.error,
+        });
+        return;
+      }
+
+      if (definition.version !== versionCheck.version) {
+        definition.version = versionCheck.version;
+        const saved = await saveTheme({ notify: false });
+        if (!saved) return;
+      }
+
+      if (!savedFolder) {
+        const saved = await saveTheme({ notify: false });
+        if (!saved || !savedFolder) return;
+      }
+
+      publishStatusMessage = 'Packaging theme archive...';
       const baseThemesDir = await themesDirectory();
       const themeFolder = await path.join(baseThemesDir, savedFolder);
       const themeId = savedFolder || toSafeName(definition.name);
@@ -3425,7 +3513,7 @@
         workshopId: definition.workshopId,
         name: definition.name,
         description: definition.description || '',
-        version: definition.version || '1.0.0',
+        version: versionCheck.version,
         apiVersion: definition.apiVersion || '2.0.0',
         tags: definition.tags ?? [],
         allowForking: definition.allowForking !== false,
@@ -3435,6 +3523,8 @@
         },
       });
 
+      lastPublishedVersion = versionCheck.version;
+
       if (result.themeId) {
         // Persist the server-assigned ID so the next publish updates this
         // workshop record instead of creating another one.
@@ -6988,7 +7078,8 @@
             </div>
           </div>
           <p class="text-[10px] leading-relaxed text-muted-foreground/70">
-            These details come from the Theme tab. Change them there before publishing.
+            These details come from the Theme tab. Published versions cannot be reused, so increase
+            the version before every update.
           </p>
         </div>