feat: pSEO CMS — SSG architecture with git templates + DuckDB

# Conflicts:
#	web/pyproject.toml

CHANGELOG.md

@@ -53,6 +53,24 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
   (`rate_peak`, `rate_off_peak`, `avg_utilisation_pct`, `courts_typical`); adds
   `_dataSource` and `_currency` metadata keys
 
+### Changed
+- **pSEO CMS: SSG architecture** — templates now live in git as `.md.jinja` files with YAML
+  frontmatter (slug, data_table, url_pattern, etc.) instead of SQLite `article_templates` table;
+  data comes directly from DuckDB serving tables instead of intermediary `template_data` table;
+  admin template views are read-only (edit in git, preview/generate in admin)
+- **pSEO CMS: SEO pipeline** — article generation bakes canonical URLs, hreflang links (EN + DE),
+  JSON-LD structured data (Article, FAQPage, BreadcrumbList), and Open Graph tags into each
+  article's `seo_head` column at generation time; articles stored with `template_slug`, `language`,
+  and `date_modified` columns for regeneration and freshness tracking
+
+### Removed
+- `article_templates` and `template_data` SQLite tables (migration 0018) — replaced by git
+  template files + direct DuckDB reads; `template_data_id` FK removed from `articles` and
+  `published_scenarios` tables
+- Admin template CRUD routes (create/edit/delete) and CSV upload — replaced by read-only views
+  with generate/regenerate/preview actions
+- `template_form.html` and `template_data.html` admin templates
+
 ### Changed
 - **Extraction: one file per source** — replaced monolithic `execute.py` with per-source
   modules (`overpass.py`, `eurostat.py`, `playtomic_tenants.py`, `playtomic_availability.py`);