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

packages/plugins/sdk/src/protocol.ts

@@ -606,7 +606,7 @@ export interface WorkerToHostMethods {
     result: IssueComment[],
   ];
   "issues.createComment": [
-    params: { issueId: string; body: string; companyId: string },
+    params: { issueId: string; body: string; companyId: string; authorAgentId?: string },
     result: IssueComment,
   ];
 

packages/plugins/sdk/src/testing.ts

@@ -405,7 +405,7 @@ export function createTestHarness(options: TestHarnessOptions): TestHarness {
         if (!isInCompany(issues.get(issueId), companyId)) return [];
         return issueComments.get(issueId) ?? [];
       },
-      async createComment(issueId, body, companyId) {
+      async createComment(issueId, body, companyId, options) {
         requireCapability(manifest, capabilitySet, "issue.comments.create");
         const parentIssue = issues.get(issueId);
         if (!isInCompany(parentIssue, companyId)) {
@@ -416,7 +416,7 @@ export function createTestHarness(options: TestHarnessOptions): TestHarness {
           id: randomUUID(),
           companyId: parentIssue.companyId,
           issueId,
-          authorAgentId: null,
+          authorAgentId: options?.authorAgentId ?? null,
           authorUserId: null,
           body,
           createdAt: now,

packages/plugins/sdk/src/types.ts

@@ -909,7 +909,12 @@ export interface PluginIssuesClient {
     companyId: string,
   ): Promise<Issue>;
   listComments(issueId: string, companyId: string): Promise<IssueComment[]>;
-  createComment(issueId: string, body: string, companyId: string): Promise<IssueComment>;
+  createComment(
+    issueId: string,
+    body: string,
+    companyId: string,
+    options?: { authorAgentId?: string },
+  ): Promise<IssueComment>;
   /** Read and write issue documents. Requires `issue.documents.read` / `issue.documents.write`. */
   documents: PluginIssueDocumentsClient;
 }

packages/plugins/sdk/src/worker-rpc-host.ts

@@ -610,8 +610,8 @@ export function startWorkerRpcHost(options: WorkerRpcHostOptions): WorkerRpcHost
           return callHost("issues.listComments", { issueId, companyId });
         },
 
-        async createComment(issueId: string, body: string, companyId: string) {
-          return callHost("issues.createComment", { issueId, body, companyId });
+        async createComment(issueId: string, body: string, companyId: string, options?: { authorAgentId?: string }) {
+          return callHost("issues.createComment", { issueId, body, companyId, authorAgentId: options?.authorAgentId });
         },
 
         documents: {