Promote AgentCompany-New to the repository root and retire the old app

The legacy application - its src, tests, landing site, promo assets, docs,
release tooling, CI workflows, and root configs - leaves the tree; it stays
reachable in history. Everything under AgentCompany-New moves up unchanged:
same package name, so the production userData/database path is untouched,
and e2e/build scripts already resolved paths relative to the project. The
developer cred.txt stays gitignored at its new location. Full verify:ci
passes from the new root.

src/main/database/migrations/022-provider-rate-limit-observations.ts

@@ -0,0 +1,21 @@
+export const providerRateLimitObservationSchema = `
+  create table if not exists provider_rate_limit_observations (
+    id text primary key,
+    org_id text not null references organizations(id) on delete cascade,
+    provider_id text not null references providers(id) on delete cascade,
+    provider_key text not null,
+    model text,
+    request_limit integer,
+    remaining_requests integer,
+    reset_at text,
+    retry_after_ms integer,
+    raw_state_json text not null,
+    observed_at text not null
+  );
+
+  create index if not exists idx_provider_rate_limit_observations_org_provider
+    on provider_rate_limit_observations(org_id, provider_id, observed_at desc);
+
+  insert into schema_migrations(version, name, applied_at)
+  values (22, 'provider_rate_limit_observations', datetime('now'));
+`;