feat(ground-suite): redesign observability console

ground-suite/README.md

@@ -6,9 +6,9 @@ identifier is `dev.kaptan.ground_suite`.
 ## Current scope
 
 The first vertical slice is a **read-only observability console**. It uses a
-deterministic replay fixture to present a vehicle identity, heartbeat state,
-telemetry presence, ordinary logs, runtime errors, and orderly-shutdown
-observations. It never sends bytes to a vehicle.
+deterministic replay fixture to present a reported vehicle identity and
+heartbeat, telemetry presence, ordinary logs, runtime errors, and
+orderly-shutdown observations. It never sends bytes to a vehicle.
 
 This is deliberate: the current F722 firmware rejects every inbound MAVLink
 frame, and `kaptan-sitl serve` has no MAVLink endpoint. A connected-looking UI
@@ -20,7 +20,7 @@ must not suggest the vehicle is controllable, safe, armed, or writable.
 VehicleDataPort (replay now; MAVLink adapter later)
         -> typed observation-or-drop updates
         -> Riverpod observability state
-        -> Overview / Diagnostics presentation
+        -> Vehicle observation / Event stream presentation
 ```
 
 `MavlinkByteSource` and `MavlinkEventDecoder` are receive-only seams. The
@@ -48,12 +48,31 @@ will be added only with their respective CI coverage.
 ## Appearance
 
 Ground Suite supplies light and dark themes and follows the operating system
-by default. Its dark palette uses near-black, muted-silver, and restrained
-green accents; translucent, locally blurred panels keep operational content
-legible without turning diagnostics into decoration.
+by default. Its dark palette pairs a near-black canvas with muted-silver text
+and restrained green accents. The visual system is intentionally layered:
+locally blurred glass is reserved for persistent navigation and session
+chrome, while vehicle facts and the event stream use opaque instrument
+surfaces for reliable scanning at volume.
 
-Use the appearance button in the observation bar to select **System default**,
-**Light**, or **Dark**. The choice applies for the current session only.
+Use **Appearance** in the desktop rail or compact session strip to select
+**System default**, **Light**, or **Dark**. The choice applies for the current
+session only.
+
+## Replay workspace
+
+The shell keeps provenance and authority visible before any detail:
+
+- **Vehicle observation** presents the replay source, last reported heartbeat,
+  observed data streams, and ingress accounting. Typed replay marks integrity
+  as not evaluated; reported state is not a current safety authority.
+- **Event stream** is a dense, copyable diagnostic timeline. Logs, runtime
+  errors, and orderly shutdown reports remain distinct, and bounded delivery
+  flags such as truncation and coalescing remain visible. The app retains a
+  bounded local history, prioritising runtime errors and shutdown reports, and
+  discloses local UI evictions separately from vehicle-side delivery loss.
+- **Vehicle setup · unavailable** is explanatory text, not a disabled control.
+  It accurately reflects that this firmware currently accepts no inbound
+  MAVLink authority.
 
 ## Deliberately deferred work