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/components/transcript/RunTranscriptView.test.tsx

@@ -81,4 +81,33 @@ describe("RunTranscriptView", () => {
       text: "Working on the task.",
     });
   });
+
+  it("renders successful result summaries as markdown in nice mode", () => {
+    const html = renderToStaticMarkup(
+      <ThemeProvider>
+        <RunTranscriptView
+          density="compact"
+          entries={[
+            {
+              kind: "result",
+              ts: "2026-03-12T00:00:02.000Z",
+              text: "## Summary\n\n- fixed deploy config\n- posted issue update",
+              inputTokens: 10,
+              outputTokens: 20,
+              cachedTokens: 0,
+              costUsd: 0,
+              subtype: "success",
+              isError: false,
+              errors: [],
+            },
+          ]}
+        />
+      </ThemeProvider>,
+    );
+
+    expect(html).toContain("<h2>Summary</h2>");
+    expect(html).toContain("<li>fixed deploy config</li>");
+    expect(html).toContain("<li>posted issue update</li>");
+    expect(html).not.toContain("result");
+  });
 });