docs: put MinIO first-class on ground, add executive overview

Treat MinIO as existing stack infrastructure (default T3 warehouse, not
on the drone), add a one-page executive map, and record placement as an
open team question rather than a rip-and-replace.

docs/01-problem-statement.md

@@ -28,7 +28,7 @@ Plus everything a platform needs around that: reproducible builds and deployment
 - The current on-board software is **Docker Compose** with two services: **sensor ingestion** and **video-stream object detection** (a YOLO-like model; weights and approaches vary).
 - **DuckDB** is already in use for local data handling.
 - **Parquet** adoption is at the evaluation stage — the storage layout in this proposal is the core of what is being asked.
-- **MinIO** is available and considered as the inter-drone sync mechanism.
+- **MinIO** is already in the stack. Exact placement (ground vs on-board vs sync path) was not fully specified in the brief; this proposal treats MinIO as **first-class ground-warehouse infrastructure** by default and keeps on-board MinIO as an open option — see [00 — Executive](00-executive.md) and [09 — Open questions](09-open-questions.md).
 - A **lightweight Kubernetes** exists in the ecosystem; this proposal scopes it to ground infrastructure only (see [02 — Architecture](02-architecture.md)).
 - After landing, each drone's data is **offloaded to an on-prem warehouse** for replay and iterative model training.
 - Mission intent (declarative goals) reaches the swarm over a narrow **C2 channel**; there is no continuous ground link in flight.
@@ -43,6 +43,7 @@ Plus everything a platform needs around that: reproducible builds and deployment
 | A4 | Missions are bounded (battery), so a "flight" is the natural unit of data lifecycle | Return-to-base on low energy implies discrete flight sessions |
 | A5 | Mission logic consumes the data platform as a service and is out of scope here | Flight control, planning, and model training are separate concerns |
 | A6 | A development-only telemetry channel exists on the bench and is absent from production builds | Standard practice; production radio profile carries C2 + swarm data plane only |
+| A7 | **MinIO's primary home is the ground warehouse (T3), not the drone** | On-board object store competes with flight-critical CPU/RAM; local Parquet + DuckDB already cover the hot path. On-board MinIO is not excluded if ops already depend on an S3 API in Compose |
 
 ## Out of scope