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_client/analysis_options.yaml

@@ -0,0 +1,16 @@
+# Defines a default set of lint rules enforced for
+# projects at Google. For details and rationale,
+# see https://github.com/dart-lang/pedantic#enabled-lints.
+
+# For lint rules and documentation, see http://dart-lang.github.io/linter/lints.
+# Uncomment to specify additional rules.
+# linter:
+#   rules:
+#     - camel_case_types
+
+analyzer:
+  exclude:
+    - lib/src/protocol/**
+
+formatter:
+  trailing_commas: preserve