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.Skills/Catalog/SkillCatalog.cs

@@ -0,0 +1,39 @@
+using Microsoft.EntityFrameworkCore;
+using TeamUp.Modules.Skills.Domain;
+using TeamUp.Modules.Skills.Persistence;
+using TeamUp.SharedKernel.Ai;
+
+namespace TeamUp.Modules.Skills.Catalog;
+
+/// <summary>Resolves skill prompts by key (latest version) for the assembler.</summary>
+internal sealed class SkillCatalog(SkillsDbContext db) : ISkillCatalog
+{
+    public async Task<IReadOnlyList<SkillPrompt>> GetByKeysAsync(
+        IReadOnlyCollection<string> keys,
+        CancellationToken cancellationToken = default)
+    {
+        if (keys.Count == 0)
+        {
+            return [];
+        }
+
+        var wanted = keys.ToHashSet();
+        var skills = await db.Skills.Where(s => wanted.Contains(s.SkillKey)).ToListAsync(cancellationToken);
+
+        return skills
+            .GroupBy(s => s.SkillKey)
+            .Select(group => group.OrderByDescending(s => s.Version, StringComparer.Ordinal).First())
+            .Select(s =>
+            {
+                var primary = s.Actions.Count > 0 ? s.Actions[0] : null;
+                return new SkillPrompt(
+                    s.SkillKey,
+                    s.Name,
+                    s.Body,
+                    primary?.Name ?? "respond",
+                    (primary?.Risk ?? ActionRisk.Draft).ToString(),
+                    s.Roles);
+            })
+            .ToList();
+    }
+}

src/Modules/TeamUp.Modules.Skills/SkillsModule.cs

@@ -3,10 +3,12 @@ using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
+using TeamUp.Modules.Skills.Catalog;
 using TeamUp.Modules.Skills.Endpoints;
 using TeamUp.Modules.Skills.Indexing;
 using TeamUp.Modules.Skills.Persistence;
 using TeamUp.Modules.Skills.Sync;
+using TeamUp.SharedKernel.Ai;
 using TeamUp.SharedKernel.Modularity;
 using TeamUp.SharedKernel.Persistence;
 
@@ -27,6 +29,7 @@ public sealed class SkillsModule : IModule
         services.AddSingleton<ISkillEmbedder, HashingSkillEmbedder>();
         services.AddScoped<SkillIndexer>();
         services.AddScoped<SkillSyncService>();
+        services.AddScoped<ISkillCatalog, SkillCatalog>();
         services.TryAddSingleton(TimeProvider.System);
     }