Harden the seams a project sweep surfaced

A systematic review of the whole codebase (main process, renderer,
IPC/migration/packaging seams) surfaced four real defects; each is
fixed at its root:

- Legacy catalogue drift: the operator's profile still carried 89
  active skills from the removed ~/.agents import era next to the 228
  built-ins. Catalogue sync now mirrors the bundle - actives whose slug
  the bundle does not ship retire (bindings keep resolving via their
  pinned revisions; retired skills leave list_skills and cannot be
  granted anew)
- Broken-bundle guard: staging now refuses a bundle without the
  humanizer skill, so an empty or quarantined resources folder can
  never trigger the mirror pass into retiring a healthy catalogue
- Duplicate agent names: @mentions, DM routing, and task assignment all
  resolve by name, so createAgent and updateAgent renames now reject a
  name already held by an active agent (case-insensitive); the mention
  resolver still refuses to guess between legacy duplicates
- Stale DM titles: agent-to-agent conversation rows titled themselves
  from the frozen creation-time space name, so renames never reached
  the sidebar; direct titles now derive from members' current names

Verified clean in the same sweep: IPC surface (82 channels, handler +
preload + api aligned), per-migration transactions with rollback,
quota-parking month rollover, retry-budget counting, meeting spot
reuse across floor-plan rebuilds.

src/main/services/builtin-skills.ts

@@ -29,6 +29,8 @@ export interface StagedBuiltinSkill {
 export interface BuiltinSkillSyncReport {
   imported: number;
   skipped: number;
+  /** Active skills retired because the bundle no longer carries their slug. */
+  retired: number;
   failures: string[];
 }
 
@@ -57,12 +59,24 @@ export function stageBuiltinSkillsLibrary(sourceRoot: string, libraryRoot: strin
     }
     staged.push(...stageCategorySkills(sourceDir, libraryRoot, seen));
   }
+  // A bundle without the forced house-style skill is a broken install, not a
+  // small catalogue. Failing here keeps the import (and the mirror-retire
+  // pass) from wiping a healthy org catalogue against an empty directory.
+  if (!seen.has("humanizer")) {
+    throw new Error(`Built-in skills bundle at ${sourceRoot} is missing the humanizer skill - refusing to sync a broken bundle.`);
+  }
   return staged;
 }
 
-/** Publishes every staged skill the org does not already carry. */
+/**
+ * Makes the org catalogue mirror the bundle: publishes every staged skill
+ * the org does not carry yet, then retires active skills whose slug the
+ * bundle no longer ships (legacy ~/.agents imports, removed skills).
+ * Existing bindings pin revisions directly and keep working; retired skills
+ * simply leave list_skills and stop being grantable.
+ */
 export function importStagedSkills(skills: SkillService, orgId: string, staged: StagedBuiltinSkill[]): BuiltinSkillSyncReport {
-  const report: BuiltinSkillSyncReport = { imported: 0, skipped: 0, failures: [] };
+  const report: BuiltinSkillSyncReport = { imported: 0, skipped: 0, retired: 0, failures: [] };
   for (const unit of staged) {
     try {
       if (skills.hasSkill(orgId, unit.slug)) {
@@ -75,6 +89,7 @@ export function importStagedSkills(skills: SkillService, orgId: string, staged:
       report.failures.push(`${unit.slug}: ${error instanceof Error ? error.message : String(error)}`);
     }
   }
+  report.retired = skills.retireSkillsNotIn(orgId, staged.map((unit) => unit.slug)).length;
   return report;
 }
 

src/main/services/organization-service.ts

@@ -76,6 +76,7 @@ export class OrganizationService {
 
   createAgent(input: CreateAgentInput): string {
     assertUsableMentionName(input.name);
+    this.assertAgentNameAvailable(input.orgId, input.name, null);
     const hiringPolicy = this.governance.enforceHiringPolicy(input);
     const id = createId("agt");
     const now = new Date().toISOString();
@@ -154,7 +155,10 @@ export class OrganizationService {
     if (!role) throw new Error("Agent role is required.");
     const name = input.name === undefined ? agent.name : input.name.trim();
     if (!name) throw new Error("Agent name is required.");
-    if (name !== agent.name) assertUsableMentionName(name);
+    if (name !== agent.name) {
+      assertUsableMentionName(name);
+      this.assertAgentNameAvailable(input.orgId, name, input.agentId);
+    }
     if (input.modelProviderId) {
       const provider = this.db.prepare("select id from providers where id = ? and org_id = ?")
         .get(input.modelProviderId, input.orgId) as { id: string } | undefined;
@@ -330,6 +334,19 @@ export class OrganizationService {
     if (goalId && project.goal_id !== goalId) throw new Error("Project is linked to a different goal.");
   }
 
+  /**
+   * Agent names are identities: @mentions, DM routing, and task assignment
+   * all resolve by name, so two active agents must never share one.
+   */
+  private assertAgentNameAvailable(orgId: string, name: string, exceptAgentId: string | null): void {
+    const clash = this.db.prepare(`
+      select id from agents
+      where org_id = ? and lifecycle = 'active' and lower(name) = lower(?) and (? is null or id <> ?)
+      limit 1
+    `).get(orgId, name.trim(), exceptAgentId, exceptAgentId) as { id: string } | undefined;
+    if (clash) throw new Error(`An active agent named "${name.trim()}" already exists. Pick a different name.`);
+  }
+
   private addAgentToWorkspaceSpaces(orgId: string, agentId: string): void {
     const spaces = this.db.prepare("select id from chat_spaces where org_id = ? and visibility = ? and space_type <> ?")
       .all(orgId, "workspace", "direct") as Array<{ id: string }>;

src/main/services/skill-service.ts

@@ -48,6 +48,34 @@ export class SkillService {
     return Boolean(this.db.prepare("select id from skill_definitions where org_id = ? and slug = ?").get(orgId, slug));
   }
 
+  /**
+   * Retires every active skill whose slug is not in `keepSlugs`, so the org
+   * catalogue mirrors the shipped bundle. Bindings pin revisions directly
+   * and keep resolving; retired skills leave list_skills and cannot be
+   * granted anew. Returns the retired slugs.
+   */
+  retireSkillsNotIn(orgId: string, keepSlugs: string[]): string[] {
+    const keep = new Set(keepSlugs);
+    const active = this.db.prepare("select id, slug from skill_definitions where org_id = ? and status = 'active'")
+      .all(orgId) as Array<{ id: string; slug: string }>;
+    const retired: string[] = [];
+    for (const skill of active) {
+      if (keep.has(skill.slug)) continue;
+      this.db.prepare("update skill_definitions set status = 'retired' where id = ?").run(skill.id);
+      this.audit.record({
+        orgId,
+        entityType: "skill_definition",
+        entityId: skill.id,
+        actorType: "system",
+        actorId: null,
+        action: "retired",
+        payload: { slug: skill.slug, reason: "not_in_builtin_bundle" },
+      });
+      retired.push(skill.slug);
+    }
+    return retired;
+  }
+
   importManifest(orgId: string, directoryPath: string, manifest: SkillManifest, explicitSlug?: string): string {
     const slug = explicitSlug ?? slugify(manifest.name);
     if (!slug) throw new Error("Skill name could not be derived.");