feat: persist blocked executor jobs

docs/architecture/memind-orchestrator-boundary.md

@@ -102,6 +102,20 @@ not a deployment backend. The compile-time dispatch capability remains false,
 so creating a job records `blocked` state without importing an executor SDK,
 launching a process, or touching a workspace.
 
+Phase 3.3 persists that state in the Orchestrator-owned PostgreSQL database.
+LangGraph checkpoint tables and `executor_jobs` share the isolated
+`memind_orchestrator` schema and credentials, but remain behind separate
+storage interfaces and readiness probes. This is a deployment simplification,
+not a domain ownership leak: neither store can access Memind business tables,
+and the Executor Job Store can move to a separate database without changing
+the graph or the Memind-facing protocol.
+
+The `build_plan` node creates the deterministic preview job
+`<runId>:executor-preview` with idempotency key
+`<runId>:build_plan:v1`. The stored result is terminal `blocked` state with
+`executor_dispatch_not_implemented`; it is a durable audit and recovery
+boundary, not an execution claim.
+
 The implemented internal API is:
 
 ```text
@@ -123,8 +137,9 @@ validate_run -> build_plan -> finalize_run
 ```
 
 It requires `policy.executionMode=observe-only` and
-`policy.sideEffectsAllowed=false`. It projects the Native executor boundary but
-cannot call Goosed, Aider, OpenHands, Tool Gateway, or the filesystem.
+`policy.sideEffectsAllowed=false`. It projects the Native executor boundary and
+persists a blocked Executor Job, but cannot dispatch Goosed, Aider, OpenHands,
+Tool Gateway, or the filesystem.
 
 ## Failure isolation
 
@@ -139,7 +154,8 @@ failure:
    service URL boundary.
 
 Successful observations are projected as `workflow_shadow_completed`; graph
-checkpoints stay in the Orchestrator-owned PostgreSQL database.
+checkpoints and blocked Executor Jobs stay in the Orchestrator-owned PostgreSQL
+database.
 
 Both terminal projection events contain bounded observation latency. The
 Memind-owned observability service aggregates those events and may join them to