feat: surface task execution progress across Host Agent and Cloud

Host Agent now persists step-level execution detail locally (via a real
TaskMetadataStore/Timeline wired into TaskRunner) and reports a bounded
in-progress snapshot piggybacked on lease renewal. Cloud persists that
snapshot per active assignment and exposes it through the existing task
list/detail query path; Cloud Console renders it as a live badge. Host
Agent's local console gains authenticated, read-only task list and
detail/timeline pages (same-origin, server-rendered) with inlined
screenshots.

Also fixes a pre-existing gap in the shared Timeline: the actual
per-step LLM prompt is now recorded instead of the task goal, benefiting
both Runtime and Host Agent consoles. When a host uses the cloud planner
transport, each decide call's prompt and resulting tool decision are
durably logged in a new planner_decision_log table (with bounded
retention) and browsable from Cloud Console; direct-transport hosts
explicitly surface a "not reported" state.

Includes Alembic migrations 0008 (progress columns on scheduled_tasks)
and 0009 (planner_decision_log), bounded Host-Agent-local retention,
dual-backend repository parity, and Vitest + pytest coverage. Task 6.5
(manual end-to-end device verification) remains.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/device-host-agent/host_agent/lease.py

@@ -11,6 +11,7 @@ import httpx
 from cloud.internal_api.models import AssignmentModel
 from host_agent.assignment import AssignmentExecutionResult
 from host_agent.client import HostAgentAPIError, HostAgentClient, StaleLeaseError
+from host_agent.progress import TaskProgressSnapshot
 
 
 class InterruptibleAssignmentExecutor(Protocol):
@@ -21,6 +22,8 @@ class InterruptibleAssignmentExecutor(Protocol):
         should_stop: Callable[[], bool] | None = None,
     ) -> AssignmentExecutionResult: ...
 
+    def latest_progress(self) -> TaskProgressSnapshot | None: ...
+
 
 class LeaseGuard:
     def __init__(self) -> None:
@@ -92,7 +95,9 @@ class ActiveAssignmentRunner:
             if done:
                 return
             try:
-                response = await self.client.renew(assignment)
+                response = await self.client.renew(
+                    assignment, progress=self.executor.latest_progress()
+                )
             except StaleLeaseError:
                 guard.mark_lost("lease rejected by control plane")
                 return