Implement SAND-WP-0003: validation meta-framework extraction

Port e2e-framework schema, runner, and reporter into wise-validator with
sand-boxer CLI integration, validate run CLI, unit tests, registry capability,
and operator docs.

README.md

@@ -1 +1,41 @@
-Agent first usecase based e2e test and health framework.
+# wise-validator
+
+Cross-repo use-case validation for Coulomb — health polling, test execution, and
+State Hub reporting on environments established by [sand-boxer](https://gitea.coulomb).
+
+**Charter:** `INTENT.md`
+
+## Quick start
+
+```bash
+make setup && make install   # validate CLI → ~/.local/bin
+
+# Requires sand-boxer on PATH: cd ~/sand-boxer && make install
+export SANDBOXER_HOST=coulombcore
+export SANDBOXER_COMPOSE_CMD=podman-compose
+
+validate run ~/activity-core
+```
+
+## Commands
+
+```bash
+validate run <repo>              # full e2e validation
+validate run <repo> --keep       # skip sandbox destroy
+validate run <repo> --no-report  # skip State Hub
+validate version
+```
+
+## Layout
+
+- `src/wisevalidator/` — schema, runner, reporter, sand-boxer client
+- `docs/runbooks/validate-compose-e2e.md` — operator runbook
+- `docs/integrations/sand-boxer.md` — sibling boundary
+
+## Development
+
+```bash
+make check    # lint + test
+make test
+make lint
+```