fix(tasks): render icons for every issue mention

[janburzinski]

Description

Render the provider icon for every canonical issue mention in the initial conversation field. The resolver previously recognized only the primary linked issue, so a second Linear issue fell back to the generic issue icon

Related issues

ENG-1857

Screenshot

Checklist

• I kept this PR small and focused
• I ran a self-review before opening this PR
• I ran the relevant local checks or explained why not
• Docs are not affected
• I added or updated tests when behavior changed
• I only added comments where the logic is not obvious
• I used Conventional Commits for the commit and PR title

[greptile-apps]

Greptile Summary

This PR updates issue mention icons in the initial conversation field.

• Resolves each issue mention token with the shared issue parser.
• Renders provider icons for every canonical issue mention, not only the linked issue.
• Adds a test for two Linear issue mentions.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.
• Unknown or malformed issue providers fall back to the existing generic issue icon instead of breaking rendering.
• The added shared import is already renderer-safe and has no runtime side effects.

Important Files Changed

Filename	Overview
apps/emdash-desktop/src/renderer/features/tasks/task-config/initial-conversation-section.tsx	Uses the shared issue mention parser to render provider icons for any canonical issue mention token.
apps/emdash-desktop/src/renderer/features/tasks/task-config/initial-conversation-section.test.ts	Adds test coverage for rendering provider icons on multiple Linear issue mentions.

_{Reviews (1): Last reviewed commit: "fix(tasks): render icons for every issue..." | Re-trigger Greptile}

[arnestrickmann]

nice!