[codex] Filter document artifacts from issue outputs (#7608)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Issue detail pages promote certain artifact work products into the
dedicated Output surface while also listing raw attachments below
> - Document-like artifacts such as plan markdown can currently be
promoted like binary outputs, which makes the same work product story
look like both an output and a document/attachment
> - The output surface should stay focused on inspectable generated
media, archives, PDFs, WebAssembly, SVG/images, and true binary
deliverables while document-like artifacts remain in the document or
attachment flow
> - This pull request filters document-like artifact metadata out of the
Output section and avoids duplicating the attachments that back promoted
outputs
> - The benefit is a cleaner issue detail page where plans and markdown
reports do not appear as binary outputs, while real output files still
get highlighted

## Linked Issues or Issue Description

Fixes #7609
Refs PAP-10354
Refs PAP-10369

## What Changed

- Added output MIME-type normalization and eligibility checks for issue
artifact work products.
- Filtered markdown, text, JSON, XML, CSV, YAML, source-like files, and
generic binary artifacts with document-like filenames out of promoted
issue outputs.
- Kept video, image including SVG, PDF, ZIP, WebAssembly, and true
binary artifacts eligible for the Output section.
- Hid attachments that back promoted outputs while leaving filtered
document-like artifact attachments visible.
- Preserved the full image attachment set for chat image gallery lookup
even when promoted image outputs are hidden from the attachment list.
- Added focused tests for output eligibility, glyph labeling, output
promotion, attachment filtering, gallery image preservation, and the
output section render behavior.

## Verification

- `pnpm vitest run ui/src/lib/issue-output.test.ts
ui/src/pages/IssueDetail.test.tsx
ui/src/components/issue-output/IssueOutputSection.test.tsx`
- GitHub PR checks are green on
`7d1b80f9702f20ab86cc502bffce599b13f1b088`.
- Greptile confidence score is 5/5 and both Greptile review threads are
resolved.

## Risks

- Low risk. The change only affects UI classification of Paperclip
artifact work products. The main behavioral risk is an uncommon
text-like generated artifact no longer appearing in the Output section;
it remains available through the normal attachment/document surfaces.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

OpenAI GPT-5 Codex via Paperclip CodexCoder, with repository tool use
and local command execution.

## 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 run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

ui/src/pages/IssueDetail.tsx

@@ -70,6 +70,7 @@ import { IssueDocumentsSection } from "../components/IssueDocumentsSection";
 import { IssuePlanDecompositionsSection } from "../components/IssuePlanDecompositionsSection";
 import { IssueOutputSection } from "../components/issue-output/IssueOutputSection";
 import { isImageAttachment } from "../lib/issue-attachments";
+import { getPromotedOutputAttachmentIds } from "../lib/issue-output";
 import { IssueSiblingNavigation } from "../components/IssueSiblingNavigation";
 import { IssuesList } from "../components/IssuesList";
 import { AgentIcon } from "../components/AgentIconPicker";
@@ -2877,8 +2878,12 @@ export function IssueDetail() {
     commentComposerRef.current?.focus();
   }, [detailTab, pendingCommentComposerFocusKey]);
 
-  const attachmentList = attachments ?? [];
-  const imageAttachments = attachmentList.filter(isImageAttachment);
+  const promotedOutputAttachmentIds = useMemo(() => getPromotedOutputAttachmentIds(workProducts), [workProducts]);
+  const attachmentList = useMemo(
+    () => (attachments ?? []).filter((attachment) => !promotedOutputAttachmentIds.has(attachment.id)),
+    [attachments, promotedOutputAttachmentIds],
+  );
+  const imageAttachments = useMemo(() => (attachments ?? []).filter(isImageAttachment), [attachments]);
 
   const handleChatImageClick = useCallback(
     (src: string) => {