Run the gate, the editor suite and the three games on the Gitea runner

The job image (tools/ci/Dockerfile, label game-maker-ci) carries chromium with the Vulkan
drivers, php-cli and the host's fonts; the render device itself comes from the runner's
container.options, so a job container gets the Intel GPU instead of llvmpipe.

tools/ci/serve.sh puts the checkout behind /game-maker/ with php -S and writes the project
shells the seeders need; every tool now takes its server from GAME_MAKER_BASE_URL rather than
from a project id repeated in shell scripts.

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

tools/lib/projects.mjs

@@ -24,12 +24,14 @@ export const PROJECTS = {
 export const DEFAULT_BASE_URL = 'https://nockal.com/game-maker/';
 
 /**
- * Reads `[projectId] [baseUrl]` from argv, falling back to `defaultId`. Targeting the playground
- * aborts: no tool may overwrite or mutate it.
+ * Reads `[projectId] [baseUrl]` from argv, falling back to `defaultId` and to
+ * `GAME_MAKER_BASE_URL` – which is how CI points every tool at its own server without
+ * repeating the project ids in shell scripts. Targeting the playground aborts: no tool may
+ * overwrite or mutate it.
  */
 export function cliArgs(script, defaultId) {
   const projectId = process.argv[2] ?? defaultId;
-  const baseUrl = process.argv[3] ?? DEFAULT_BASE_URL;
+  const baseUrl = process.argv[3] ?? process.env.GAME_MAKER_BASE_URL ?? DEFAULT_BASE_URL;
   if (projectId === PROJECTS.playground) {
     console.error(`refusing to run ${script} against the playground project (${PROJECTS.playground}).`);
     process.exit(2);