feat: LinkedIn profile search engine (Django + React + Elasticsearch + ELK)

Full-stack implementation of the Cyberyan full-stack trial task.

Backend (Django 5 / DRF)
- Normalised PostgreSQL model (Profile, Company, School, Skill, Experience,
  Education) as the source of truth, with GIN + trigram indexes.
- Self-healing CSV reader: the supplied export carries an injected watermark
  column, missing columns, rows split by broken quoting and a duplicated
  header. A signature-scored Needleman-Wunsch alignment reconstructs 284 clean
  records out of 336 physical rows; only 10 rows parse correctly without it.
- Pluggable search layer (Strategy): Elasticsearch by default, PostgreSQL
  full-text search as a fallback selected by a single environment variable.
- Keyword search with per-field boosts, fuzziness and phrase boosting, six
  faceted filters (OR within a filter, AND across filters), an experience
  range, four sort orders, highlighting and facet aggregations.
- JWT auth with rotation + blacklist, three roles, PII masking, scoped rate
  limits, a single error envelope, OpenAPI schema and health probes.

Frontend (React 18 / TypeScript / Vite)
- Debounced search with type-ahead, faceted filter panel, result cards,
  profile drawer, URL-synced search state, automatic token refresh.
- Highlight snippets rendered without dangerouslySetInnerHTML.

Infrastructure
- Hardened multi-stage images (non-root, read-only rootfs, healthchecks).
- docker-compose for the full stack plus dev and production overlays.
- ELK: structured JSON logs shipped asynchronously to Logstash, routed per
  event type, with a composable index template and a Kibana setup script.

Quality
- 61 backend tests (85% coverage), ruff/black/bandit/mypy, ESLint + tsc,
  GitHub Actions running lint, tests and both image builds.
- Persian documentation: README plus architecture, search, API, data,
  security and operations guides.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GnFo6fNaHCTAkJbfcdkqtG

frontend/nginx.conf

@@ -0,0 +1,68 @@
+# -----------------------------------------------------------------------------
+# Serves the SPA and proxies /api to the Django container.
+#
+# Putting both behind one origin means the browser never issues a cross-origin
+# request, so no CORS pre-flight, no third-party cookie rules, and the API can
+# keep its allow-list empty in production.
+# -----------------------------------------------------------------------------
+server {
+    listen 8080;
+    server_name _;
+
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # --- Security headers ----------------------------------------------------
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-Frame-Options "DENY" always;
+    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+    add_header Permissions-Policy "camera=(), microphone=(), geolocation=(), interest-cohort=()" always;
+    # The bundle is fully self-hosted, so the policy can stay strict.
+    add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; connect-src 'self'; font-src 'self'; frame-ancestors 'none'; base-uri 'self'; form-action 'self'" always;
+
+    server_tokens off;
+    client_max_body_size 2m;
+
+    gzip on;
+    gzip_types text/css application/javascript application/json image/svg+xml;
+    gzip_min_length 1024;
+
+    location = /healthz {
+        access_log off;
+        add_header Content-Type text/plain;
+        return 200 'ok';
+    }
+
+    # Hashed assets never change under the same name - cache them hard.
+    location /assets/ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+        try_files $uri =404;
+    }
+
+    location /api/ {
+        proxy_pass http://backend:8000;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header X-Request-ID $request_id;
+        proxy_connect_timeout 5s;
+        proxy_read_timeout 30s;
+    }
+
+    # Django admin and API documentation share the backend origin.
+    location ~ ^/(admin|static)/ {
+        proxy_pass http://backend:8000;
+        proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+
+    # Client-side routing: unknown paths fall back to the SPA shell.
+    location / {
+        try_files $uri $uri/ /index.html;
+        add_header Cache-Control "no-cache";
+    }
+}