feat(docs): Add comprehensive documentation for Vexer, Vulnerability Explorer, and Zastava modules

- Introduced AGENTS.md, README.md, TASKS.md, and implementation_plan.md for Vexer, detailing mission, responsibilities, key components, and operational notes.
- Established similar documentation structure for Vulnerability Explorer and Zastava modules, including their respective workflows, integrations, and observability notes.
- Created risk scoring profiles documentation outlining the core workflow, factor model, governance, and deliverables.
- Ensured all modules adhere to the Aggregation-Only Contract and maintain determinism and provenance in outputs.

docs/modules/scanner/operations/entrypoint-lang-nginx.md

@@ -0,0 +1,24 @@
+# Entry-Point Runtime — Nginx
+
+## Signals to gather
+- `argv0` equals `nginx`.
+- Config files: `/etc/nginx/nginx.conf`, `conf.d/*.conf`, `/usr/share/nginx/html`.
+- Environment (`NGINX_ENTRYPOINT_QUIET_LOGS`, `NGINX_PORT`, `NGINX_ENVSUBST_TEMPLATE`).
+- Listening sockets on 80/443 (dynamic mode) or `EXPOSE 80` (static).
+- Modules or scripts shipped with the official Docker entrypoint (`docker-entrypoint.sh` collapsing to `nginx -g "daemon off;"`).
+
+## Implementation notes
+- Parse `nginx.conf` (basic directive traversal) to extract worker processes, include chains, upstream definitions.
+- Handle official entrypoint idioms (`envsubst` templating) via ShellFlow.
+- Distinguish pure reverse proxies from PHP-FPM combos; when both `nginx` and `php-fpm` run, classify container as `Supervisor`.
+- Record static web content presence (`/usr/share/nginx/html/index.html`).
+
+## Evidence & scoring
+- Boost for confirmed config and workers.
+- Add evidence for templating features, env substitution, or modules.
+- Penalise if binary exists without config (likely not the entry point).
+
+## Edge cases
+- Alpine images may place configs under `/etc/nginx/conf.d`; include both.
+- Custom builds might rename binary (`openresty`, `tengine`); consider aliases if common.
+- Windows Nginx not supported; fall back to `Other`.