Agent profiles (AGENTS.md): per-org library, free builtins, versioning, marketplace, persona

Reusable agent definitions authored as AGENTS.md (YAML frontmatter + a Markdown body that becomes
the agent's operating guide). Mirrors the skill library, including its review hardening.

- AgentProfile entity (OrgBoard): org-scoped + versioned by (OrganizationId, ProfileKey, Version),
  NULLS NOT DISTINCT unique index; Origin Builtin|Authored|Installed; ProfileVisibility +
  ProfileStatus with the Public⟹Published invariant enforced in Apply()/SetVisibility(). AGENTS.md
  parser (YamlDotNet). AgentProfileWriter is the single upsert path (insert-only mode for install).
- Free builtins: AgentProfileSeeder seeds Aria (PO), Quill (QA), Edison (backend) on startup via a
  new IStartupSeeder + SeederRunner (runs after migrations). Idempotent, null-org, visible to all.
- Endpoints (/api/orgboard/agent-profiles): upload, list (resolvable-winner order), get versions,
  publish/unpublish, fork, marketplace (per-(key,version) AlreadyInLibrary), install (insert-only →
  clean 409, no clobber). ConfigureAgents to author/manage; ViewBoard to browse; audited.
- Persona: Agent gains Persona; ConfigureAgent stores it; AgentRunContext carries it; PromptAssembler
  injects it as "# Operating guide" (data, not instructions) so an applied profile shapes the run.
- Client: Agent profiles page (library + marketplace tabs, upload editor, publish/unlist/fork/install),
  routed + in the nav.

Verified: ArchitectureTests 8/8, IntegrationTests 55/55 (new AgentProfilesTests: builtins seeded,
upload + validation, publish, cross-org marketplace list→install→private copy, duplicate 409, per-
version flag, Member 403; persona renders as the operating guide), client build green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/components/AppShell.tsx

@@ -2,6 +2,7 @@ import type { ReactNode } from 'react'
 import { Link, useLocation } from 'react-router'
 import {
   BookMarked,
+  BookUser,
   Bot,
   Boxes,
   ChartColumn,
@@ -43,6 +44,7 @@ export function AppShell({ children }: { children: ReactNode }) {
           <NavItem icon={Inbox} label="Cartable" to="/cartable" />
           <NavItem icon={ShieldCheck} label="Review inbox" to="/reviews" />
           <NavItem icon={Bot} label="AI seats" to="/seats" />
+          <NavItem icon={BookUser} label="Agent profiles" to="/agent-profiles" />
           <NavItem icon={BookMarked} label="Skills" to="/skills" />
           <NavItem icon={Network} label="Org chart" to="/org" />
           <NavItem icon={Boxes} label="Structure" to="/structure" />