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/config.py

@@ -43,6 +43,10 @@ class HostAgentConfig:
     runtime_host: str = "127.0.0.1"
     runtime_port: int = 8000
     dependency_restart_max_attempts: int = 5
+    task_progress_db_path: Path = Path("host_agent_data/task_progress.sqlite3")
+    task_artifact_dir: Path = Path("host_agent_data/history")
+    task_retention_max_count: int = 50
+    task_retention_max_age_days: int = 7
 
 
 def load_host_agent_config(
@@ -135,6 +139,23 @@ def load_host_agent_config(
         dependency_restart_max_attempts=_positive_int(
             values, "HOST_AGENT_DEPENDENCY_RESTART_MAX_ATTEMPTS", 5
         ),
+        task_progress_db_path=Path(
+            values.get(
+                "HOST_AGENT_TASK_PROGRESS_DB_PATH",
+                "host_agent_data/task_progress.sqlite3",
+            ).strip()
+        ),
+        task_artifact_dir=Path(
+            values.get(
+                "HOST_AGENT_TASK_ARTIFACT_DIR", "host_agent_data/history"
+            ).strip()
+        ),
+        task_retention_max_count=_positive_int(
+            values, "HOST_AGENT_TASK_RETENTION_MAX_COUNT", 50
+        ),
+        task_retention_max_age_days=_positive_int(
+            values, "HOST_AGENT_TASK_RETENTION_MAX_AGE_DAYS", 7
+        ),
     )
     if config.max_retry_backoff_seconds < config.retry_backoff_seconds:
         raise HostAgentConfigurationError(