feat!: move query/logs/routes/diagram/agent-view endpoints under /environments/{envSlug}/

P3C — the last data/query wave of the taxonomy migration. Every user-
facing read endpoint that was keyed on env-as-query-param is now under
the env-scoped URL, making env impossible to omit and unambiguous in
server-side tenant+env filtering.

Server:
- SearchController: /api/v1/search/** → /api/v1/environments/{envSlug}/...
  Endpoints: /executions (GET), /executions/search (POST), /stats,
  /stats/timeseries, /stats/timeseries/by-app, /stats/timeseries/by-route,
  /stats/punchcard, /attributes/keys, /errors/top. Env comes from path.
- LogQueryController: /api/v1/logs → /api/v1/environments/{envSlug}/logs.
- RouteCatalogController: /api/v1/routes/catalog → /api/v1/environments/
  {envSlug}/routes. Env filter unconditional (path).
- RouteMetricsController: /api/v1/routes/metrics →
  /api/v1/environments/{envSlug}/routes/metrics (and /metrics/processors).
- DiagramRenderController: /{contentHash}/render stays flat (hashes are
  globally unique). Find-by-route moved to /api/v1/environments/{envSlug}/
  apps/{appSlug}/routes/{routeId}/diagram — the old GET /diagrams?...
  handler is removed.
- Agent views split cleanly:
  - AgentListController (new): /api/v1/environments/{envSlug}/agents
  - AgentEventsController: /api/v1/environments/{envSlug}/agents/events
  - AgentMetricsController: /api/v1/environments/{envSlug}/agents/
    {agentId}/metrics — now also rejects cross-env agents (404) as a
    defense-in-depth check, fulfilling B3.
  Agent self-service endpoints (register/refresh/heartbeat/deregister)
  remain flat at /api/v1/agents/** — JWT-authoritative.

SPA:
- queries/agents.ts, agent-metrics.ts, logs.ts, catalog.ts (route
  metrics only; /catalog stays flat), processor-metrics.ts,
  executions.ts (attributes/keys, stats, timeseries, search),
  dashboard.ts (all stats/errors/punchcard), correlation.ts,
  diagrams.ts (by-route) — all rewritten to env-scoped URLs.
- Hooks now either read env from useEnvironmentStore internally or
  require it as an argument. Query keys include env so switching env
  invalidates caches.
- useAgents/useAgentEvents signature simplified — env is no longer a
  parameter; it's read from the store. Callers (LayoutShell,
  AgentHealth, AgentInstance) updated accordingly.
- LogTab and useStartupLogs thread env through to useLogs.
- envFetch helper introduced in executions.ts for env-prefixed raw
  fetch until schema.d.ts is regenerated against the new backend.

BREAKING CHANGE: All these flat paths are removed:
  /api/v1/search/**, /api/v1/logs, /api/v1/routes/catalog,
  /api/v1/routes/metrics (and /processors), /api/v1/diagrams
  (lookup), /api/v1/agents (list), /api/v1/agents/events-log,
  /api/v1/agents/{id}/metrics, /api/v1/agent-events.
Clients must use the /api/v1/environments/{envSlug}/... equivalents.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ui/src/pages/AgentHealth/AgentHealth.tsx

@@ -163,7 +163,7 @@ export default function AgentHealth() {
   const navigate = useNavigate();
   const { toast } = useToast();
   const selectedEnv = useEnvironmentStore((s) => s.environment);
-  const { data: agents } = useAgents(undefined, appId, selectedEnv);
+  const { data: agents } = useAgents(undefined, appId);
   const { data: appConfig } = useApplicationConfig(appId, selectedEnv);
   const updateConfig = useUpdateApplicationConfig();
 
@@ -282,7 +282,7 @@ export default function AgentHealth() {
   }, [appConfig, configDraft, updateConfig, toast, appId]);
   const [eventSortAsc, setEventSortAsc] = useState(false);
   const [eventRefreshTo, setEventRefreshTo] = useState<string | undefined>();
-  const { data: events } = useAgentEvents(appId, undefined, 50, eventRefreshTo, selectedEnv);
+  const { data: events } = useAgentEvents(appId, undefined, 50, eventRefreshTo);
 
   const [appFilter, setAppFilter] = useState('');
   type AppSortKey = 'status' | 'name' | 'tps' | 'cpu' | 'heartbeat';

ui/src/pages/AgentInstance/AgentInstance.tsx

@@ -45,8 +45,8 @@ export default function AgentInstance() {
   const timeTo = timeRange.end.toISOString();
 
   const selectedEnv = useEnvironmentStore((s) => s.environment);
-  const { data: agents, isLoading } = useAgents(undefined, appId, selectedEnv);
-  const { data: events } = useAgentEvents(appId, instanceId, 50, eventRefreshTo, selectedEnv);
+  const { data: agents, isLoading } = useAgents(undefined, appId);
+  const { data: events } = useAgentEvents(appId, instanceId, 50, eventRefreshTo);
 
   const agent = useMemo(
     () => (agents || []).find((a: any) => a.instanceId === instanceId) as any,