fix(search): apply task privacy to artifact results (#20595)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Private tasks are visible only to the people and agents that have
access
> - Company search already filters task results by the caller's task
read condition
> - Artifact results (agent documents, work products and attachments) in
search, and the company artifacts list, did not use that condition
> - So a company member could find a private task's document title and
snippet through search
> - This pull request applies the same task read condition to artifact
results
> - The benefit is that private task outputs stay private in search and
in the artifacts list

## Linked Issues or Issue Description

**What happened**
An agent saved a document on a private task. A different company member
without access to that task searched for a word in the document. The
search returned the document as an artifact result with a snippet.

**Expected behavior**
Search and the artifacts list show artifacts only from tasks the caller
can read.

**Steps to reproduce**
1. Create a private task and let an agent save a document on it.
2. Sign in as a company member who cannot read the task.
3. Search for a word in the document, or open the company artifacts
list.
4. See the private document in the results.

## What Changed

- `company-search.ts`: artifact counts and artifact rows apply
`options.issueReadCondition`.
- `routes/companies.ts`: `GET /companies/:companyId/artifacts` passes
the caller's `issueReadSqlCondition` to the artifacts service.

## Verification

- Red then green: `cd server && npx vitest run
src/__tests__/company-search-service.test.ts -t "private task
artifacts"` (fails on `master` with the private document in the
outsider's results).
- Red then green: `npx vitest run
src/__tests__/company-artifacts-service.test.ts -t "caller can read"`.
- `npx vitest run src/__tests__/company-search-service.test.ts
src/__tests__/company-search-extract-service.test.ts
src/__tests__/company-search-extract-routes.test.ts
src/__tests__/company-artifacts-service.test.ts` (all pass).
- `tsc --noEmit -p server`: no errors in the changed files.

## Risks

- Low risk. The read condition is the same one task results use. Callers
with full access (local board, instance admin, privacy mode off) get
`true` and see no change.

## Model Used

- Anthropic Claude Opus 5.5 (`claude-opus-5-5`), tool use and code
execution in Claude Code.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

server/src/services/company-artifacts.ts

@@ -195,7 +195,7 @@ function pageByCursor<T extends { id: string; updatedAt: string }>(
   return { page, nextCursor };
 }
 
-async function loadIssueGroupingRows(db: Db, companyId: string, seedIssueIds: Iterable<string>) {
+async function loadIssueGroupingRows(db: Db, companyId: string, seedIssueIds: Iterable<string>, readCondition?: SQL) {
   const rowsById = new Map<string, IssueGroupingRow>();
   let pending = [...new Set(seedIssueIds)];
 
@@ -209,7 +209,7 @@ async function loadIssueGroupingRows(db: Db, companyId: string, seedIssueIds: It
         updatedAt: issues.updatedAt,
       })
       .from(issues)
-      .where(and(eq(issues.companyId, companyId), inArray(issues.id, pending)));
+      .where(and(eq(issues.companyId, companyId), inArray(issues.id, pending), readCondition));
 
     const nextPending = new Set<string>();
     for (const row of rows) {
@@ -321,7 +321,8 @@ export function companyArtifactsService(db: Db, storage?: StorageService) {
     list: async (
       companyId: string,
       rawQuery: Partial<CompanyArtifactsQuery> = {},
-      options: { issueConditions?: SQL[]; userId?: string } = {},
+      /** `readCondition` limits artifacts and group tasks to tasks the caller can read. */
+      options: { issueConditions?: SQL[]; readCondition?: SQL; userId?: string } = {},
     ): Promise<CompanyArtifactsResponse> => {
       const query = companyArtifactsQuerySchema.parse(rawQuery);
       const cursor = decodeCursor(query.cursor);
@@ -344,6 +345,7 @@ export function companyArtifactsService(db: Db, storage?: StorageService) {
         isNull(issues.hiddenAt),
         isNull(issues.harnessKind),
         ...(options.issueConditions ?? []),
+        ...(options.readCondition ? [options.readCondition] : []),
       ];
       const artifacts: CompanyArtifact[] = [];
       const artifactSortDates = new Map<string, string>();
@@ -742,7 +744,7 @@ export function companyArtifactsService(db: Db, storage?: StorageService) {
 
       const issueSeedIds = new Set(artifacts.map((artifact) => artifact.issue.id));
       if (query.groupIssueId) issueSeedIds.add(query.groupIssueId);
-      const issueRows = await loadIssueGroupingRows(db, companyId, issueSeedIds);
+      const issueRows = await loadIssueGroupingRows(db, companyId, issueSeedIds, options.readCondition);
       const groups = buildArtifactGroups({
         artifacts: sorted,
         companyPrefix: company.issuePrefix,

server/src/services/company-search.ts

@@ -951,6 +951,7 @@ export function companySearchService(db: Db) {
           eq(issues.companyId, companyId),
           visibleIssueCondition(),
           ...artifactIssueFilters,
+          ...(options?.issueReadCondition ? [options.issueReadCondition] : []),
         ];
         const documentArtifactConditions = [
           eq(issueDocuments.companyId, companyId),
@@ -1035,7 +1036,7 @@ export function companySearchService(db: Db) {
         const result = await companyArtifactsService(db).list(companyId, {
           q: normalizedQuery.slice(0, COMPANY_ARTIFACTS_MAX_QUERY_LENGTH),
           limit: Math.min(fetchLimit, COMPANY_ARTIFACTS_MAX_LIMIT),
-        }, { issueConditions: issueFilters });
+        }, { issueConditions: issueFilters, readCondition: options?.issueReadCondition });
         return result.artifacts;
       }