fix(kobo): strip leading v from server version in koreader plugin

The KOReader plugin's update check response provides the server version,
which already contains a leading "v". The update and plugin popups in
the KOReader plugin format the version with an explicit "v" prefix,
resulting in a "vv" typo (e.g. "vv1.2.0").

Strip the leading "v" from the server version in the updater script
if present to ensure it is displayed with a single "v" prefix.

Closes #644

koreader-plugin/bookorbit.koplugin/bookorbit_updater.lua

@@ -211,7 +211,7 @@ function UpdateCheck:doCheckForUpdate()
 end
 
 function UpdateCheck:handleUpdateVersionResponse(body, interactive, prompt_allowed)
-    local server_ver = body.serverVersion or "unknown"
+    local server_ver = tostring(body.serverVersion or "unknown"):gsub("^v", "")
     local plugin_latest = body.pluginVersion
     self.settings.update_check_last_at = os.time()
 

server/src/modules/koreader/koreader-plugin-source.test.ts

@@ -182,6 +182,14 @@ describe('KOReader plugin update source wiring', () => {
     expect(updater).toContain('self.settings.update_dismissed_version = plugin_latest');
   });
 
+  it('renders the server version with exactly one v prefix in update dialogs', async () => {
+    const updater = await readPluginFile('bookorbit_updater.lua');
+
+    expect(updater).toContain('local server_ver = tostring(body.serverVersion or "unknown"):gsub("^v", "")');
+    expect(updater).toContain('Plugin is up to date (v%1).\\nServer: v%2');
+    expect(updater).toContain('Update available: v%1 -> v%2\\nServer: v%3');
+  });
+
   it('runs a throttled update check after successful full-library sweeps', async () => {
     const main = await readPluginFile('main.lua');
     const sweep = await readPluginFile('bookorbit_sweep.lua');