Add single-binary build and --port flag

bun build --compile bundles the app and Bun runtime into bin/job-board
(plus linux-x64/arm64 targets). New src/main.ts entry: serve (default)
or 'scrape' once, with --port/-p overriding PORT. A compiled binary
stores its database in data/ next to the executable.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scrapper/package.json

@@ -3,9 +3,12 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "start": "bun run src/server.ts",
-    "dev": "bun --watch run src/server.ts",
-    "scrape": "bun run src/scrape.ts"
+    "start": "bun run src/main.ts",
+    "dev": "bun --watch run src/main.ts",
+    "scrape": "bun run src/scrape.ts",
+    "build": "bun build src/main.ts --compile --minify --sourcemap --outfile bin/job-board",
+    "build:linux-x64": "bun build src/main.ts --compile --minify --sourcemap --target=bun-linux-x64 --outfile bin/job-board-linux-x64",
+    "build:linux-arm64": "bun build src/main.ts --compile --minify --sourcemap --target=bun-linux-arm64 --outfile bin/job-board-linux-arm64"
   },
   "devDependencies": {
     "@types/bun": "latest"