fix(admin): render Leaflet maps in template preview

The .card wrapper has overflow:hidden which clips Leaflet's
absolutely-positioned tile layers. Override to overflow:visible
on the rendered-article card. Add .catch() to map fetch calls.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ## [Unreleased]
 
 ### Fixed
+- **Admin template preview maps** — Leaflet maps rendered blank in admin preview due to `.card` `overflow: hidden` clipping tile layers. Set `overflow: visible` on the rendered-article card. Also added `.catch()` handlers to map fetch calls so failures are logged to console.
 - **Pipeline diagnostic script** (`scripts/check_pipeline.py`) — handle DuckDB catalog naming quirk where `lakehouse.duckdb` uses catalog `lakehouse` instead of `local`, causing SQLMesh logical views to break. Script now auto-detects the catalog via `USE`, and falls back to querying physical tables (`sqlmesh__<schema>.<table>__<hash>`) when views fail.
 - **Eurostat gas prices extractor** — `nrg_pc_203` filter missing `unit` dimension (API returns both KWH and GJ_GCV); now filters to `KWH`.
 - **Eurostat labour costs extractor** — `lc_lci_lev` used non-existent `currency` filter dimension; corrected to `unit: EUR`.