Replace supervisor with agentrun worker service

Move agent-run orchestration from the legacy supervisor path into the new
agentrun worker/service package and wire it through coredata, server,
policies, and GraphQL resolvers.

This consolidates run lifecycle handling around lease-aware workers and
aligns API surface with the new agent-run domain model so reviewers can
follow one coherent execution path.

Signed-off-by: Bryan Frimin <bryan@probo.com>

pkg/coredata/migrations/20260607T060000Z.sql

@@ -0,0 +1,17 @@
+-- Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+-- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+-- AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+-- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+-- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+-- OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+-- PERFORMANCE OF THIS SOFTWARE.
+
+ALTER TABLE agent_runs
+	ADD COLUMN lease_generation BIGINT NOT NULL DEFAULT 0,
+	DROP COLUMN lease_owner;