feat(ext-vite): replace the web bundler with a Vite extension and its Maven plugin

flash-ext-vite runs Vite's dev server in DEV and otherwise serves the build from the
classpath, read straight from the directory or jar with no manifest. The Maven plugin
flash-ext-vite-maven-plugin builds the frontend at prepare-package and packages it
there, so mvn package makes a jar that serves its own frontend and mvn test needs no
Node. Three overrides remain (root, devPort, basePath); the package manager is read
from the nearest lockfile.

Serving fixes what the bundler got wrong: Vite's hashed files under assets/ are
cached as immutable instead of revalidated, HEAD reports the real Content-Length, a
missing asset is a 404 instead of the index, 304s carry ETag and Cache-Control, and
gzip respects q=0 and is prepared at boot. Every response header is pre-encoded, so
serving allocates nothing, which is what Response.type(byte[]) is for. Vite stops
with the app through onClose, and a lockfile change reinstalls before restarting.

The modes, strategies, logging and command-safety options, the asset-source
abstraction, the manifest and the Jackson dependency are gone: 1,535 lines of main
code become 480, plus 84 for the plugin.

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

flash-extensions/pom.xml

@@ -27,7 +27,8 @@
         <module>flash-ext-view-jte</module>
         <module>flash-ext-view-thymeleaf</module>
         <module>flash-ext-limiter</module>
-        <module>flash-ext-web-bundler</module>
+        <module>flash-ext-vite</module>
+        <module>flash-ext-vite-maven-plugin</module>
         <module>flash-ext-mcp</module>
         <module>flash-ext-validation</module>
         <module>flash-ext-scheduler</module>
@@ -119,7 +120,7 @@
             </dependency>
             <dependency>
                 <groupId>dev.relism</groupId>
-                <artifactId>flash-ext-web-bundler</artifactId>
+                <artifactId>flash-ext-vite</artifactId>
                 <version>${project.version}</version>
             </dependency>
             <dependency>