Rename public discovery app from "finder" to "koja"

Rebrand the public café-discovery app: directories web/finder→web/koja and
docker/finder→docker/koja, plus all service wiring (docker-compose, Caddy
subdomain koja.meezi.ir, env vars KOJA_PORT / NEXT_PUBLIC_KOJA_URL, CI
workflows) and the app's display name (Koja / کجا).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -58,20 +58,20 @@ jobs:
         env:
           NEXT_PUBLIC_API_URL: http://localhost:5080
 
-  # ── Finder: typecheck ──────────────────────────────────────────────────────
-  finder:
-    name: Finder (Next.js typecheck)
+  # ── Koja: typecheck ─────────────────────────────────────────────────────────
+  koja:
+    name: Koja (Next.js typecheck)
     runs-on: ubuntu-latest
     defaults:
       run:
-        working-directory: web/finder
+        working-directory: web/koja
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
           node-version: "20"
           cache: npm
-          cache-dependency-path: web/finder/package-lock.json
+          cache-dependency-path: web/koja/package-lock.json
       - run: npm install --legacy-peer-deps --ignore-scripts
       - run: npx tsc --noEmit
         env: