Consolidate backend: drop vendored APwhy, converge on goose + sqlc

Phase 0 cleanup verified end-to-end:

- Delete vendored APwhy runtime (cmd/apwhy, internal/apwhy) and the
  unwired copy (internal/api/server.go + static bundle + cloned
  internal/{storage,analytics,auth,rbac}) — ~7.5k lines of dead code.
- Keep Containr's native internal/gateway; move APwhy management
  routes under /api/v1/gateway/* so they stop colliding with the
  native /services paths. Fix handlers against the real schema:
  UUID ids via RETURNING, integer enabled flags, plan validation,
  service validate endpoint, unique-violation mapping.
- Port agents.go off GORM onto sqlc (sqlc/queries/agents.sql);
  drop gorm dependencies; fix sqlc schema drift (services.environment_id).
- Replace the SELECT 1 goose baseline with the real consolidated
  schema (52 tables) minus APwhy's parallel auth/RBAC objects;
  idempotent via IF NOT EXISTS / OR REPLACE / guarded DO blocks so it
  replays cleanly over legacy installs. Add a drop migration for the
  dead objects and delete the legacy filename-tracked migrations/
  loader, directory, and Dockerfile copy. Verified via cmd/migrate:
  fresh install 53 tables, legacy upgrade clean to 20260917000000.
- Canvas: add invisible React Flow handles to ServiceNode so inferred
  auto-connections stop emitting warning #008.
- Remove reactflow dep (superseded by @xyflow/react), test harness
  cmds, and legacy 0001_init.sql backups.

Authored By: TDvorak <[email protected]>

app/backend/sqlc/queries/agents.sql

@@ -0,0 +1,109 @@
+-- name: GetAgentByHostAndIP :one
+SELECT * FROM node_agents
+WHERE hostname = $1 AND ip_address = $2
+LIMIT 1;
+
+-- name: GetAgent :one
+SELECT * FROM node_agents WHERE id = $1;
+
+-- name: ListAgents :many
+SELECT * FROM node_agents ORDER BY created_at ASC;
+
+-- name: CreateAgent :one
+INSERT INTO node_agents (
+    id, name, hostname, ip_address, port, status, version,
+    capabilities, resources, last_heartbeat, metadata
+) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
+RETURNING *;
+
+-- name: UpdateAgent :one
+UPDATE node_agents SET
+    name = $2,
+    hostname = $3,
+    ip_address = $4,
+    port = $5,
+    status = $6,
+    version = $7,
+    capabilities = $8,
+    resources = $9,
+    last_heartbeat = $10,
+    metadata = $11,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING *;
+
+-- name: UpdateAgentHeartbeat :exec
+UPDATE node_agents SET
+    status = $2,
+    resources = $3,
+    last_heartbeat = $4,
+    updated_at = NOW()
+WHERE id = $1;
+
+-- name: DeleteAgent :exec
+DELETE FROM node_agents WHERE id = $1;
+
+-- name: InsertAgentHeartbeat :exec
+INSERT INTO agent_heartbeats (
+    id, node_agent_id, timestamp, status, resources,
+    container_count, system_load, uptime, version
+) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9);
+
+-- name: ListAgentHeartbeatsSince :many
+SELECT * FROM agent_heartbeats
+WHERE node_agent_id = $1 AND timestamp >= $2
+ORDER BY timestamp ASC;
+
+-- name: ListPendingCommands :many
+SELECT * FROM agent_commands
+WHERE node_agent_id = $1 AND status = 'pending'
+ORDER BY created_at ASC
+LIMIT 25;
+
+-- name: ListCommandsForAgent :many
+SELECT * FROM agent_commands
+WHERE node_agent_id = $1
+ORDER BY created_at DESC;
+
+-- name: GetCommandForAgent :one
+SELECT * FROM agent_commands
+WHERE id = $1 AND node_agent_id = $2;
+
+-- name: CreateCommand :one
+INSERT INTO agent_commands (
+    id, type, node_agent_id, container_id, payload, status
+) VALUES ($1, $2, $3, $4, $5, 'pending')
+RETURNING *;
+
+-- name: CompleteCommand :one
+UPDATE agent_commands SET
+    status = $3,
+    result = $4,
+    error = $5,
+    completed_at = NOW(),
+    updated_at = NOW()
+WHERE id = $1 AND node_agent_id = $2
+RETURNING *;
+
+-- name: ListContainersForAgent :many
+SELECT * FROM container_instances
+WHERE node_agent_id = $1;
+
+-- name: GetContainerForAgent :one
+SELECT * FROM container_instances
+WHERE id = $1 AND node_agent_id = $2;
+
+-- name: GetContainer :one
+SELECT * FROM container_instances WHERE id = $1;
+
+-- name: CreateContainer :one
+INSERT INTO container_instances (
+    id, name, image, project_id, service_id, node_agent_id,
+    status, resources, ports, environment, volumes, networks,
+    restart_policy, health_check
+) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14)
+RETURNING *;
+
+-- name: UpdateContainerStatus :exec
+UPDATE container_instances SET status = $2, updated_at = NOW()
+WHERE id = $1;