feat(skills): add dryRun flag for scan prune path

Add a `dryRun` option to the scan-projects endpoint. When true, the
scan identifies which skills would be pruned and which agents would be
affected, but does not delete anything or modify agent configs.

The response now includes:
- `pruned[]`: list of skills that would be (or were) removed, with
  affected agent names
- `dryRun`: boolean echoed back so callers can distinguish preview
  results from live mutations

This lets callers preview destructive prune operations before committing
to them, addressing the review concern about silent deletion of
production data.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/services/company-skills.ts

@@ -17,6 +17,7 @@ import type {
   CompanySkillImportResult,
   CompanySkillListItem,
   CompanySkillProjectScanConflict,
+  CompanySkillProjectScanPruned,
   CompanySkillProjectScanRequest,
   CompanySkillProjectScanResult,
   CompanySkillProjectScanSkipped,
@@ -1860,8 +1861,10 @@ export function companySkillService(db: Db) {
       ? await projects.listByIds(companyId, input.projectIds)
       : await projects.list(companyId);
     const workspaceFilter = new Set(input.workspaceIds ?? []);
+    const dryRun = input.dryRun === true;
     const skipped: CompanySkillProjectScanSkipped[] = [];
     const conflicts: CompanySkillProjectScanConflict[] = [];
+    const pruned: CompanySkillProjectScanPruned[] = [];
     const warnings: string[] = [];
     const imported: CompanySkill[] = [];
     const updated: CompanySkill[] = [];
@@ -2043,6 +2046,18 @@ export function companySkillService(db: Db) {
         for (const skill of skillsAtSource) {
           if (currentSlugs.has(skill.slug)) continue;
           const usedByAgents = await usage(companyId, skill.key);
+          const affectedAgentNames = usedByAgents.map((a) => a.name);
+
+          pruned.push({
+            skillId: skill.id,
+            slug: skill.slug,
+            key: skill.key,
+            sourceLocator: skill.sourceLocator,
+            affectedAgents: affectedAgentNames,
+          });
+
+          if (dryRun) continue;
+
           if (usedByAgents.length > 0) {
             // Detach the skill from all agents that have it, then delete
             for (const agent of usedByAgents) {
@@ -2059,7 +2074,7 @@ export function companySkillService(db: Db) {
               }
             }
             warnings.push(
-              `Skill "${skill.slug}" was removed from ${sourceLocator} and detached from ${usedByAgents.map((a) => a.name).join(", ")}.`,
+              `Skill "${skill.slug}" was removed from ${sourceLocator} and detached from ${affectedAgentNames.join(", ")}.`,
             );
           } else {
             warnings.push(
@@ -2082,7 +2097,9 @@ export function companySkillService(db: Db) {
       updated,
       skipped,
       conflicts,
+      pruned,
       warnings,
+      dryRun,
     };
   }