Add template-driven document creation to the RDM duties tab

Why: the duties tab only listed existing documents — rdm.docs.instantiate
had no UI entry, so a fresh project showed an empty duties tab with no
setup path (owner trial feedback 2026-10-15).

Evidence: new docs-instantiate-params tests green; full vitest run shows
only the 12 pre-existing conversation-work failures also present at clean
HEAD; design-guard green.

Impact: duties tab gains a template picker + title input wired to
rdm.docs.instantiate (backend command rdm.docs.templates lists published
identities); instantiation refreshes the catalog and selects the new doc.

Refs: Agent-System-RDM docs/records/dhf/u4-header-footer-slots.md

test/docs-instantiate-params.test.ts

@@ -0,0 +1,21 @@
+import { describe, expect, it } from 'vitest'
+import { docsInstantiateParams } from '../src/components/adminRdmSections'
+
+const tpl = {
+  templateId: 'dhf.2750fbaf1f67d10c', version: '1.0.0', title: '项目建议书',
+  docTypes: ['rd_proposal'], stage: '0. 商务阶段',
+}
+
+describe('docsInstantiateParams', () => {
+  it('carries docType/templateId/version and trims the title', () => {
+    expect(docsInstantiateParams(tpl, '  U5 试点项目建议书 ')).toEqual({
+      docType: 'rd_proposal', templateId: 'dhf.2750fbaf1f67d10c',
+      version: '1.0.0', title: 'U5 试点项目建议书',
+    })
+  })
+  it('omits blank titles so the backend falls back to the template title', () => {
+    const p = docsInstantiateParams(tpl, '   ')
+    expect(Object.hasOwn(p, 'title')).toBe(false)
+    expect(p).toEqual({ docType: 'rd_proposal', templateId: 'dhf.2750fbaf1f67d10c', version: '1.0.0' })
+  })
+})