Implement SAND-WP-0002 meta-framework foundation (T01–T09)

Add meta-framework spec, pydantic schemas, profile/extension YAML, extension
registry, ext.compose-ssh backend, SandboxManager with State Hub events, CLI
commands, integration docs, capability registry entry, and compose-e2e runbook.
Nine unit tests pass. T10 remote smoke test remains for operator.

.claude/rules/stack-and-commands.md

@@ -26,6 +26,16 @@ make build          # uv build (wheel + sdist)
 make cli-version    # smoke test: sandboxer version
 ```
 
+Sandbox CLI (v0):
+
+```bash
+sandboxer create --profile profile.compose-e2e --input repo=/path/to/repo
+sandboxer get <id>
+sandboxer list
+sandboxer destroy <id>
+sandboxer recreate <id>
+```
+
 Equivalent `uv` invocations without Make:
 
 ```bash