* feat(mentions): support @mentioning issues in comments
- Extend MentionItem type to include "issue" alongside "member"/"agent"
- Add issue search (by identifier and title) to mention suggestion dropdown
- Render issue mentions with CircleDot icon in autocomplete popup
- Issue mentions serialize as [MUL-117 Title](mention://issue/id) (no @ prefix)
- Markdown renderer shows issue mentions as clickable links to /issues/:id
- Backend mentionRe regex updated to match issue mention type
* feat(mentions): auto-expand issue identifiers and add mention format to agent instructions
1. Path A — CLAUDE.md template (runtime_config.go):
Add a "## Mentions" section teaching agents the mention serialization
format for issues, members, and agents. All agents automatically
receive this via the auto-generated CLAUDE.md.
2. Approach 2 — Server-side auto-conversion (internal/mention/):
New ExpandIssueIdentifiers() utility that scans comment content for
bare issue identifiers (e.g. MUL-117) and replaces them with
[MUL-117](mention://issue/<uuid>) mention links. Skips code blocks,
inline code, and existing markdown links. Integrated into both:
- handler.CreateComment (HTTP API path)
- service.createAgentComment (agent task output path)