feat(meditate): Meditate's server, its sealed tables, and SimpleLogin's way back to it

halkyon_meditate_server and its generated client, copied from Todo's
and stripped to the module, the register and the sync engine (ADR 0038,
D1, D7): content_key, meditate_settings and sitting, synced and sealed,
each indexing spaceId and deleted with the person's space; two
migrations, the initial one and sittings (purely additive, the ADR
explains the SQL); ports 8280 to 8282 and PostgreSQL 8290 (D13).
Tests: the module's basics naming `meditate`, the sync engine refusing
calls without a session, the register's modes, and a person's deletion
taking their rows alone.

halkyon_base's forwarding page knows Meditate's ways back
(meditate-loopback on 43826, meditate-scheme app.halkyon.meditate),
which halkyon_app's repository names among the apps' ports.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/meditate/halkyon_meditate_server/analysis_options.yaml

@@ -0,0 +1,21 @@
+# The workspace's lint rules (see ../../../analysis_options.yaml), minus generated code.
+include: ../../../analysis_options.yaml
+
+analyzer:
+  exclude:
+    - lib/src/generated/**
+    - test/integration/test_tools/serverpod_test_tools.dart
+
+# Serverpod's code generator reads this package with an analyzer that doesn't know
+# Dart v3.13's primary constructors yet, and fails on them in endpoint files, so the
+# server keeps the classic constructor and class-body syntax, as Learn's does; switch
+# these back on once Serverpod parses it.
+linter:
+  rules:
+    empty_container_bodies: false
+    unnecessary_type_name_in_constructor: false
+    use_declaring_parameters: false
+    use_primary_constructors: false
+
+formatter:
+  trailing_commas: preserve