[AZ-577] [AZ-578] [AZ-579] [AZ-580] Implement E2E test batch 2

Adds 26 blackbox tests (FT-P-01..18, FT-N-01..08) covering full AC
matrices for Vehicles/Missions/Waypoints/Health/Errors. Three
spec-vs-code carry-forwards documented in batch_02_report.md and
pinned with [Trait("carry_forward", ...)].

Shared scaffolding: ApiDtos.cs, AssertProblemEnvelopeAsync helper,
Seeds.cs, StubSchema.cs, CascadeF3/F4 fixtures, PostgresStopStart
fixture (gated by COMPOSE_RESTART_ENABLED). Removes the 4 placeholder
Sanity.cs files (now superseded). docker-compose.test.yml gains the
expected_results volume mount + FIXTURE_SQL_DIR for the consumer.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/Azaion.Missions.E2E.Tests/Fixtures/StubSchema.cs

@@ -0,0 +1,45 @@
+using Npgsql;
+
+namespace Azaion.Missions.E2E.Fixtures;
+
+/// <summary>
+/// Creates the borrowed-schema stub tables (media, annotations, detection)
+/// required by the cascade-delete fixtures. The migrator (<c>DatabaseMigrator</c>)
+/// only owns the missions/vehicles/waypoints/map_objects tables; media,
+/// annotations, and detection are owned by sibling services in production
+/// (out of scope for this repo per
+/// _docs/02_document/tests/environment.md). The cascade walk in
+/// <c>MissionService.DeleteMission</c> still references them, so tests must
+/// supply their schema via side-channel.
+/// </summary>
+/// <remarks>
+/// Idempotent — every statement is <c>CREATE … IF NOT EXISTS</c>.
+/// Column shapes match the LinqToDB entities (<c>Database/Entities/Media.cs</c>,
+/// <c>Database/Entities/Annotation.cs</c>, <c>Database/Entities/Detection.cs</c>).
+/// </remarks>
+public static class StubSchema
+{
+    public static void EnsureCreated()
+    {
+        using var conn = new NpgsqlConnection(TestEnvironment.DbSideChannel);
+        conn.Open();
+        using var cmd = conn.CreateCommand();
+        cmd.CommandText = """
+            CREATE TABLE IF NOT EXISTS media (
+                id TEXT PRIMARY KEY,
+                waypoint_id UUID
+            );
+
+            CREATE TABLE IF NOT EXISTS annotations (
+                id TEXT PRIMARY KEY,
+                media_id TEXT NOT NULL
+            );
+
+            CREATE TABLE IF NOT EXISTS detection (
+                id UUID PRIMARY KEY,
+                annotation_id TEXT NOT NULL
+            );
+            """;
+        cmd.ExecuteNonQuery();
+    }
+}