fix: make regional time series discoverable

frontend/README.md

@@ -6,7 +6,7 @@ The persisted `Kempen Regional Workbench` is the automatic operational data cont
 
 The user-facing shell is task based: `Kaart`, `Bronnen`, `Kwaliteit`, `Beeldanalyse`, `Downloads`, `Status` and `Beheer`. Internal benchmark projects, raw dataset metadata, provider capabilities, model registry details and QA evidence remain accessible through labelled advanced disclosures instead of competing with the normal workflow.
 
-Detection defaults to the configured local YOLO asset and automatically selects an available raster and active model asset where possible. The model registry and preflight remain honest when PyTorch, Ultralytics, a local model file or a tile manifest is unavailable. The active building profile is operational but remains review-required: its recorded coverage-aware benchmark is approximately precision 0.590, recall 0.577 and F1 0.582 over seven positive AOIs, with zero detections in the empty-background control. Another training pass is intentionally blocked until the generated false-positive and false-negative review decisions are completed.
+Detection defaults to the configured local YOLO asset and automatically selects an available raster and active model asset where possible. The model registry and preflight remain honest when PyTorch, Ultralytics, a local model file or a tile manifest is unavailable. The active building profile is operational but remains review-required: its current coverage-aligned benchmark is approximately precision 0.614, recall 0.606 and F1 0.607 over seven positive AOIs, with zero detections in all three pure-empty controls. A reviewed challenger remains inactive because it produced two detections in empty Postel forest.
 
 Map-driven building analysis uses the documented footprint-IoU `0.25` and
 distinguishes model candidates from verified buildings. It shows persisted
@@ -20,6 +20,10 @@ current, while `Evolution` lets the operator compare an earlier and later
 snapshot from the same series over a drawn rectangle. Results show units,
 absolute/percentage change, estimate status and source limitations.
 Added/removed/modified overlays only appear for stable source identities.
+When Evolution is opened from a current-only theme, the explorer automatically
+switches to the first available persisted series. Theme cards then show either
+the number and range of historical observations or `Alleen huidige toestand`,
+so a single GRB snapshot can no longer strand the workflow in an empty state.
 When a theme has multiple valid methodologies, a compact series selector keeps
 them explicit. Forest therefore defaults to the official modern 2013-2025
 10 m series, while the separate 1778-1969 historical map series remains