Add MariaDB IPL validation, topology docs in beds.toml, and developer wiki

- Add MariaDB (REL) IPL validation — master required, secondary non-fatal
- Add RelNodeConfig / RelInstanceConfig structs with master/secondary pattern
- Add rel_services section to beds.toml and test fixture
- Add detailed topology commentary to beds.toml covering standalone,
  master/replica, Galera cluster, and multi-DB-per-node configurations
- Add developer wiki (wiki/) covering:
    - Origin story — PHP Namaste history, production record, why Rust
    - Architecture overview — full system diagram, all layers explained
    - The four nodes — appServer, admin, segundo, tercero with real-world context
    - IPL sequence — every step documented with rationale for ordering
    - Configuration system — layering, env selection, adding new sections
    - Queue topology — exchanges, routing keys, broker bindings, vhost isolation
    - Template system — REC/REL, TLA convention, cache map, warehousing
    - Event lineage — compound event IDs, parent/child tracking, msLogs schema
    - Glossary
- Update README with wiki index and MariaDB status

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

tests/fixtures/beds_test.toml

@@ -57,3 +57,17 @@ user     = "beds"
 pass     = "changeme"
 database = "beds_test"
 use_ssl  = false
+
+[rel_services.app_server.master]
+host     = "127.0.0.1"
+port     = 3306
+user     = "beds"
+pass     = "changeme"
+database = "beds_test"
+
+[rel_services.app_server.secondary]
+host     = "127.0.0.1"
+port     = 3306
+user     = "beds"
+pass     = "changeme"
+database = "beds_test"