feat(adapters): external adapter plugin system with dynamic UI parser

- Plugin loader: install/reload/remove/reinstall external adapters
  from npm packages or local directories
- Plugin store persisted at ~/.paperclip/adapter-plugins.json
- Self-healing UI parser resolution with version caching
- UI: Adapter Manager page, dynamic loader, display registry
  with humanized names for unknown adapter types
- Dev watch: exclude adapter-plugins dir from tsx watcher
  to prevent mid-request server restarts during reinstall
- All consumer fallbacks use getAdapterLabel() for consistent display
- AdapterTypeDropdown uses controlled open state for proper close behavior
- Remove hermes-local from built-in UI (externalized to plugin)
- Add docs for external adapters and UI parser contract

ui/src/adapters/hermes-local/config-fields.tsx

@@ -1,49 +0,0 @@
-import type { AdapterConfigFieldsProps } from "../types";
-import {
-  Field,
-  DraftInput,
-} from "../../components/agent-config-primitives";
-import { ChoosePathButton } from "../../components/PathInstructionsModal";
-
-const inputClass =
-  "w-full rounded-md border border-border px-2.5 py-1.5 bg-transparent outline-none text-sm font-mono placeholder:text-muted-foreground/40";
-const instructionsFileHint =
-  "Absolute path to a markdown file (e.g. AGENTS.md) that defines this agent's behavior. Injected into the system prompt at runtime.";
-
-export function HermesLocalConfigFields({
-  isCreate,
-  values,
-  set,
-  config,
-  eff,
-  mark,
-  hideInstructionsFile,
-}: AdapterConfigFieldsProps) {
-  if (hideInstructionsFile) return null;
-  return (
-    <Field label="Agent instructions file" hint={instructionsFileHint}>
-      <div className="flex items-center gap-2">
-        <DraftInput
-          value={
-            isCreate
-              ? values!.instructionsFilePath ?? ""
-              : eff(
-                  "adapterConfig",
-                  "instructionsFilePath",
-                  String(config.instructionsFilePath ?? ""),
-                )
-          }
-          onCommit={(v) =>
-            isCreate
-              ? set!({ instructionsFilePath: v })
-              : mark("adapterConfig", "instructionsFilePath", v || undefined)
-          }
-          immediate
-          className={inputClass}
-          placeholder="/absolute/path/to/AGENTS.md"
-        />
-        <ChoosePathButton />
-      </div>
-    </Field>
-  );
-}

ui/src/adapters/hermes-local/index.ts

@@ -1,12 +0,0 @@
-import type { UIAdapterModule } from "../types";
-import { parseHermesStdoutLine } from "hermes-paperclip-adapter/ui";
-import { HermesLocalConfigFields } from "./config-fields";
-import { buildHermesConfig } from "hermes-paperclip-adapter/ui";
-
-export const hermesLocalUIAdapter: UIAdapterModule = {
-  type: "hermes_local",
-  label: "Hermes Agent",
-  parseStdoutLine: parseHermesStdoutLine,
-  ConfigFields: HermesLocalConfigFields,
-  buildAdapterConfig: buildHermesConfig,
-};