feat(adapters): add capability flags to ServerAdapterModule

Replace 5 hardcoded adapter type lists with declarative capability flags
on ServerAdapterModule, enabling external adapter plugins to declare
their capabilities without modifying Paperclip source.

New optional fields on ServerAdapterModule:
- supportsInstructionsBundle: managed instructions bundle support
- instructionsPathKey: config key for instructions file path
- requiresMaterializedRuntimeSkills: skill materialization needed

Server changes:
- agents.ts: capability-aware helpers with legacy fallbacks
- adapters.ts: expose capabilities in GET /api/adapters response
- registry.ts: explicit flags on all built-in adapters

UI changes:
- New useAdapterCapabilities hook for capability lookups
- AgentDetail.tsx: replace hardcoded isLocal allowlist
- AgentConfigForm.tsx: replace NONLOCAL_TYPES denylist
- OnboardingWizard.tsx: replace NONLOCAL_TYPES denylist

All flags are optional with backwards-compatible fallbacks to the
legacy hardcoded lists for adapters that don't set them.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/pages/AgentDetail.tsx

@@ -26,6 +26,7 @@ import { AgentConfigForm } from "../components/AgentConfigForm";
 import { PageTabBar } from "../components/PageTabBar";
 import { adapterLabels, roleLabels, help } from "../components/agent-config-primitives";
 import { ToggleSwitch } from "@/components/ui/toggle-switch";
+import { useAdapterCapabilities } from "@/adapters/use-adapter-capabilities";
 import { MarkdownEditor } from "../components/MarkdownEditor";
 import { assetsApi } from "../api/assets";
 import { getUIAdapter, buildTranscript, onAdapterChange } from "../adapters";
@@ -1719,13 +1720,8 @@ function PromptsTab({
     externalBundleRef.current = null;
   }, [agent.id]);
 
-  const isLocal =
-    agent.adapterType === "claude_local" ||
-    agent.adapterType === "codex_local" ||
-    agent.adapterType === "opencode_local" ||
-    agent.adapterType === "pi_local" ||
-    agent.adapterType === "hermes_local" ||
-    agent.adapterType === "cursor";
+  const getCapabilities = useAdapterCapabilities();
+  const isLocal = getCapabilities(agent.adapterType).supportsInstructionsBundle;
 
   const { data: bundle, isLoading: bundleLoading } = useQuery({
     queryKey: queryKeys.agents.instructionsBundle(agent.id),