fix(version): preserve suffix on bump, simplify workflow version logic (#191)

version_bump.php now captures the existing suffix (e.g. -dev) from
manifest.xml and re-applies it after incrementing the base version.
This lets workflows read the version as-is instead of stripping and
re-applying suffixes based on branch names.

Simplified update-server.yml and pre-release.yml by removing the
strip→map→re-apply suffix dance. Removed DISPLAY_VERSION and SUFFIX
output variables — VERSION now carries the full suffixed string.

Authored-by: Moko Consulting
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/Unit/VersionBumpTest.php

@@ -68,7 +68,7 @@ class VersionBumpTest extends TestCase
 
         $this->execute();
         $content = file_get_contents("{$this->tmpDir}/README.md");
-        $this->assertStringContainsString('03.05.02', $content);
+        $this->assertStringContainsString('09.21.08', $content);
         $this->assertStringContainsString('Some content', $content);
     }
 
@@ -86,6 +86,22 @@ class VersionBumpTest extends TestCase
         $this->assertStringContainsString('01.00.01', $output);
     }
 
+    public function testPreservesSuffixOnBump(): void
+    {
+        mkdir("{$this->tmpDir}/.mokogitea", 0755, true);
+        file_put_contents(
+            "{$this->tmpDir}/.mokogitea/manifest.xml",
+            '<manifest><identity><version>01.02.03-dev</version></identity></manifest>'
+        );
+        $this->writeReadme('01.02.03');
+
+        $output = $this->execute();
+        $this->assertStringContainsString('01.02.04-dev', $output);
+
+        $manifest = file_get_contents("{$this->tmpDir}/.mokogitea/manifest.xml");
+        $this->assertStringContainsString('01.02.04-dev', $manifest);
+    }
+
     public function testFailsWithNoVersion(): void
     {
         file_put_contents(