Add task sync push milestone

Tasks could start from host content in 2.2.0, but there was still no post-create path to update a live workspace from the host. This change adds the next host-to-task step so repeated fix or review loops do not require recreating the task for every local change.

Add task sync push across the CLI, Python SDK, and MCP server, reusing the existing safe archive import path from seeded task creation instead of introducing a second transfer stack. The implementation keeps sync separate from workspace_seed metadata, validates destinations under /workspace, and documents the current non-atomic recovery path as delete-and-recreate.

Validation:
- uv lock
- UV_CACHE_DIR=.uv-cache uv run pytest --no-cov tests/test_cli.py tests/test_vm_manager.py tests/test_api.py tests/test_server.py tests/test_public_contract.py
- UV_CACHE_DIR=.uv-cache make check
- UV_CACHE_DIR=.uv-cache make dist-check
- real guest-backed smoke: task create --source-path, task sync push, task exec to verify both files, task delete

docs/integrations.md

@@ -30,7 +30,7 @@ Best when:
 Recommended surface:
 
 - `vm_run`
-- `task_create(source_path=...)` + `task_exec` when the agent needs persistent workspace state
+- `task_create(source_path=...)` + `task_sync_push` + `task_exec` when the agent needs persistent workspace state
 
 Canonical example:
 
@@ -65,7 +65,7 @@ Best when:
 Recommended default:
 
 - `Pyro.run_in_vm(...)`
-- `Pyro.create_task(source_path=...)` + `Pyro.exec_task(...)` when repeated workspace commands are required
+- `Pyro.create_task(source_path=...)` + `Pyro.push_task_sync(...)` + `Pyro.exec_task(...)` when repeated workspace commands are required
 
 Lifecycle note:
 
@@ -74,6 +74,8 @@ Lifecycle note:
   that final exec
 - use `create_task(source_path=...)` when the agent needs repeated commands in one persistent
   `/workspace` that starts from host content
+- use `push_task_sync(...)` when later host-side changes need to be imported into that running
+  workspace without recreating the task
 
 Examples: