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.

docs/integrations/glas-harness.md

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+# glas-harness integration
+
+glas-harness owns the agent gateway, tools, memory, and channels. sand-boxer
+delivers an isolated execution environment; the harness executes tools inside it.
+
+## Example request
+
+```bash
+sandboxer create \
+  --profile profile.agent-dev \
+  --input repo=/path/to/workspace \
+  --actor agt \
+  --project glas-harness
+```
+
+## Response fields (ready state)
+
+| Field | Owner | Description |
+|-------|-------|-------------|
+| `sandbox_id` | sand-boxer | Stable instance identifier |
+| `reachability.ssh` | sand-boxer | SSH target for harness exec channel |
+| `reachability.remote_dir` | sand-boxer | Workspace root on remote host |
+| `state` | sand-boxer | Lifecycle state (`ready`, etc.) |
+
+## Ownership
+
+| Concern | Owner |
+|---------|-------|
+| Sandbox provision / teardown | sand-boxer |
+| Tool call parsing and policies | glas-harness |
+| SSH / tunnel reachability setup | glas-harness + ops-bridge |
+| Agent memory and session state | glas-harness |
+
+## Out of scope for sand-boxer
+
+- Tool schemas and approval flows
+- Channel bridges (Slack, email, etc.)
+- Subagent orchestration