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- Remove reactflow dep (superseded by @xyflow/react), test harness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/frontend/src/features/workspace/canvas/nodes.tsx

@@ -1,4 +1,4 @@
-import type { Node, NodeProps } from '@xyflow/react';
+import { Handle, Position, type Node, type NodeProps } from '@xyflow/react';
 import type { ServiceEntity } from '@/lib/api-client';
 import { serviceStatusClass } from '@/lib/api-client';
 import { Box, ArrowUpRight, Globe, Database, Terminal, MoreHorizontal, ExternalLink } from 'lucide-react';
@@ -62,11 +62,15 @@ export function ServiceNode({ data }: NodeProps<ServiceNodeType>) {
       style={{ minWidth: 220, maxWidth: 280 }}
     >
       {/* Ambient overlay */}
-      <div 
+      <div
         className="absolute inset-0 opacity-0 group-hover:opacity-100 transition-opacity duration-300 pointer-events-none"
         style={{ background: `${typeColor}10` }}
       />
 
+      {/* Invisible connection points - required by React Flow for edge attachment */}
+      <Handle type="target" position={Position.Left} className="!opacity-0 !w-2 !h-2 !border-0" />
+      <Handle type="source" position={Position.Right} className="!opacity-0 !w-2 !h-2 !border-0" />
+
       {/* Status indicator bar at top */}
       <div 
         className={`absolute top-0 left-0 right-0 h-0.5 transition-all duration-300 ${isRunning ? 'opacity-100' : 'opacity-40'}`}