feat: initialize bangwen recruitment aggregation and search engine

- Rust core engine with HTTP ingestion gateway, hybrid search, and white-box resume matching
- Python edge collectors supporting declarative TOML and specialized adapters
- PostgreSQL schema migrations with pgvector embedding support
- Hardened security controls: strict CSP, terminal sanitization, and input boundary validation
- Multi-service container orchestration with dedicated non-root execution

.gitignore

@@ -0,0 +1,21 @@
+# Development artifacts and notes
+.dev/
+
+# Rust build artifacts
+target/
+
+# Local data & environment
+data/
+.env
+.env.local
+
+# Python artifacts (for collectors)
+__pycache__/
+*.py[cod]
+.venv/
+.uv/
+
+
+# Added by cargo
+
+/target