fix(migrations): two cold-DB regressions surfaced by Phase-9 docker compose smoke

The v2.1.0 release-gate Phase-9 docker compose smoke run against a
fresh Postgres surfaced two real defects in the migration files that
testcontainers schema-per-test never exercised. Both reproduce by
running 'docker compose down -v && docker compose up --build'
against the current master tree.

Bug A — migration 000045_users_deactivated_at.up.sql is malformed.

  The 000029 schema defines:
    permissions      (id TEXT PRIMARY KEY, name TEXT NOT NULL UNIQUE,
                      namespace TEXT NOT NULL)
    role_permissions (..., permission_id TEXT NOT NULL REFERENCES ..., ...)

  But 000045 was written as:
    INSERT INTO permissions (name) VALUES ...        -- missing id + namespace
    INSERT INTO role_permissions (role_id, permission, ...) VALUES ...
                                                       ^^ wrong column name

  On a cold-DB run this fails immediately with:
    pq: null value in column "id" of relation "permissions"
        violates not-null constraint

  Fix: provide id + namespace columns, use permission_id (the actual
  column name), ON CONFLICT (id) DO NOTHING. The new permission ids
  follow the existing 'p-auth-*' prefix convention (p-auth-user-read +
  p-auth-user-deactivate) used by 000029.

Bug B — migration 000029_rbac.up.sql is not idempotent post-000043.

  000029 originally created actor_roles with:
    UNIQUE (actor_id, actor_type, role_id, tenant_id)

  Audit 2026-05-10 HIGH-10 closure / migration 000043 drops that
  constraint and re-creates it WITH scope columns:
    UNIQUE (actor_id, actor_type, role_id, scope_type, scope_id, tenant_id)

  The migration runner (internal/repository/postgres/db.go::RunMigrations)
  is naive — no tracker table — and re-runs every *.up.sql file on
  every server boot. On the second-and-later boots, 000029's seed
  INSERT for actor-demo-anon-admin still references the
  pre-000043 constraint name in its ON CONFLICT clause:
    ON CONFLICT (actor_id, actor_type, role_id, tenant_id) DO NOTHING

  Postgres errors out with:
    pq: there is no unique or exclusion constraint matching the
        ON CONFLICT specification

  Fix: pin the conflict target to the row's primary key 'id' column
  (always present, never altered). The seed row's deterministic id
  'ar-demo-anon-admin' makes ON CONFLICT (id) work under both pre-
  and post-000043 schemas.

Why testcontainers schema-per-test missed these:

  Each test in internal/repository/postgres/*_test.go spins up a
  fresh schema and applies every .up.sql in order ONCE. The full
  '000029 -> 000043 -> retry 000029' cascade never happens because
  migrations don't re-run within a test. Phase-9 docker compose
  smoke is the only test path that exercises the server-restart-
  on-error retry, which is exactly the missing coverage.

Verify (sandbox): go test ./internal/repository/postgres/ PASS.
Workstation re-runs 'docker compose down -v && docker compose up'
to confirm both bugs are closed.

migrations/000029_rbac.up.sql

@@ -268,6 +268,16 @@ ON CONFLICT (role_id, permission_id, scope_type, scope_id) DO NOTHING;
 -- The row exists unconditionally; the env-var check happens in code.
 -- Reserved system actor: API rejects mutations / deletions targeting
 -- this id with 409 Conflict.
+-- v2.1.0 Phase-9 cold-DB-smoke fix: this ON CONFLICT used to reference
+-- UNIQUE (actor_id, actor_type, role_id, tenant_id), the constraint
+-- created by this migration. Migration 000043 (Audit 2026-05-10 HIGH-10
+-- closure) drops that constraint and re-creates it with scope_type +
+-- scope_id columns. On a re-run of this migration (which the naive
+-- file-walking RunMigrations does on every server boot), the original
+-- ON CONFLICT spec no longer matches an existing constraint and
+-- Postgres errors out. Pin the conflict target to `id` (the PK column,
+-- unconditionally present in both pre- and post-000043 schemas) so the
+-- seed stays idempotent across migration-ordering changes downstream.
 INSERT INTO actor_roles (id, actor_id, actor_type, role_id, granted_at, granted_by, tenant_id)
 VALUES (
     'ar-demo-anon-admin',
@@ -278,6 +288,6 @@ VALUES (
     'system',
     't-default'
 )
-ON CONFLICT (actor_id, actor_type, role_id, tenant_id) DO NOTHING;
+ON CONFLICT (id) DO NOTHING;
 
 COMMIT;

migrations/000045_users_deactivated_at.up.sql

@@ -19,21 +19,27 @@ BEGIN;
 ALTER TABLE users
     ADD COLUMN IF NOT EXISTS deactivated_at TIMESTAMPTZ;
 
-INSERT INTO permissions (name) VALUES
-    ('auth.user.read'),
-    ('auth.user.deactivate')
-ON CONFLICT (name) DO NOTHING;
+-- v2.1.0 Phase-9 cold-DB-smoke fix: the original commit set just
+-- (name) and used a `permission` column in role_permissions. The
+-- 000029 schema actually defines `permissions (id PK, name UNIQUE,
+-- namespace NOT NULL)` and `role_permissions (..., permission_id, ...)`.
+-- testcontainers schema-per-test never exercised this path; the cold
+-- compose-up smoke caught it on a fresh Postgres.
+INSERT INTO permissions (id, name, namespace) VALUES
+    ('p-auth-user-read',       'auth.user.read',       'auth.user'),
+    ('p-auth-user-deactivate', 'auth.user.deactivate', 'auth.user')
+ON CONFLICT (id) DO NOTHING;
 
 -- Read is broad (admin / operator / auditor).
-INSERT INTO role_permissions (role_id, permission, scope_type, scope_id) VALUES
-    ('r-admin',    'auth.user.read', 'global', NULL),
-    ('r-operator', 'auth.user.read', 'global', NULL),
-    ('r-auditor',  'auth.user.read', 'global', NULL)
-ON CONFLICT DO NOTHING;
+INSERT INTO role_permissions (role_id, permission_id, scope_type, scope_id) VALUES
+    ('r-admin',    'p-auth-user-read', 'global', NULL),
+    ('r-operator', 'p-auth-user-read', 'global', NULL),
+    ('r-auditor',  'p-auth-user-read', 'global', NULL)
+ON CONFLICT (role_id, permission_id, scope_type, scope_id) DO NOTHING;
 
 -- Deactivate is admin-only.
-INSERT INTO role_permissions (role_id, permission, scope_type, scope_id) VALUES
-    ('r-admin', 'auth.user.deactivate', 'global', NULL)
-ON CONFLICT DO NOTHING;
+INSERT INTO role_permissions (role_id, permission_id, scope_type, scope_id) VALUES
+    ('r-admin', 'p-auth-user-deactivate', 'global', NULL)
+ON CONFLICT (role_id, permission_id, scope_type, scope_id) DO NOTHING;
 
 COMMIT;