Add web frontend and Docker packaging

Frontend is a single page served from classpath resources with a JSON API
alongside it. Kept separate from the MCP tools because the consumers differ:
a model reads formatted text, a browser needs structures. Only the database
is shared.

The page has three views - catalog with edition details, copies, detected
facts with evidence and a filterable file list; script search with FTS5
snippets and a viewer; and a format breakdown. No build step, no CDN, no
dependencies; light and dark follow the system.

New `serve` command puts the frontend and MCP on one port, one process and
one database connection, which is also what the container runs. `mcp` alone
still works for a headless setup.

Docker is a two-stage build: JDK plus the Rex-EMoolator submodule to compile,
JRE for runtime. installDist rather than build, so check - and with it
verifyCoreVersion - is skipped and git is not needed in the image. The pinned
:core tag is extracted from gradle.properties at build time and passed in by
the entrypoint, otherwise copy.core_version would record "nieznana" and
derived-artifact invalidation would stop working. Properties go through
JAVA_OPTS because Gradle's launcher treats everything after the script name
as application arguments.

Compose mounts the collection read-only and keeps the database and script
cache in a named volume. The port is bound to loopback.

Not verified: the image itself does not build here, the Docker daemon is not
running on this machine. The launcher, JAVA_OPTS handling and resource
packaging were tested against the installDist output directly.

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

.dockerignore

@@ -0,0 +1,12 @@
+# submoduł vendor/ MUSI zostać — composite build kompiluje z niego :core
+.git
+.gitmodules
+.gradle
+.idea
+build
+out
+data
+collection
+vendor/Rex-EMoolator/.git
+vendor/Rex-EMoolator/build
+vendor/Rex-EMoolator/.gradle