M4: the assembler — assemble → model → parse (Increment 2)

SharedKernel contracts (so Assembler stays decoupled): IAgentRunContextProvider (agent +
task) and ISkillCatalog (skill prompts by key). Implemented by OrgBoard (AgentRunContextProvider)
and Skills (SkillCatalog).

Assembler:
- PromptAssembler builds house-style + identity + the agent's skill bodies + the task, and
  derives the primary action + risk from the agent's first skill. RAG/working-memory join at M6.
- AgentRunExecutor (real): resolve context + skills → assemble → resolve BYOK config (with
  fallback) → call IModelClient → parse into action + risk → capture all on the AgentRun.

Verified: build green; ArchitectureTests 8/8; IntegrationTests 29/29 — incl. the M4 acceptance:
assigning a Spec task to Aria (PO, gated, stub BYOK) yields a Completed run with the assembled
prompt (skill body + task title), action "write-spec", risk "Draft", and model output. Nothing
executes — the gate is M5.

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

src/Modules/TeamUp.Modules.OrgBoard/OrgBoardModule.cs

@@ -5,6 +5,8 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using TeamUp.Modules.OrgBoard.Endpoints;
 using TeamUp.Modules.OrgBoard.Persistence;
+using TeamUp.Modules.OrgBoard.Runtime;
+using TeamUp.SharedKernel.Ai;
 using TeamUp.SharedKernel.Modularity;
 using TeamUp.SharedKernel.Persistence;
 
@@ -22,6 +24,7 @@ public sealed class OrgBoardModule : IModule
 
         services.AddDbContext<OrgBoardDbContext>(options => options.UseNpgsql(connectionString));
         services.AddScoped<IModuleDbContext>(sp => sp.GetRequiredService<OrgBoardDbContext>());
+        services.AddScoped<IAgentRunContextProvider, AgentRunContextProvider>();
         services.TryAddSingleton(TimeProvider.System);
     }