[Improve] Route tasks using linked issue context

[roomote-roomote]

Opened on behalf of Daniel Riccio. Follow up by mentioning @roomote-roomote, in the web UI, or in Discord.

What changed

Pasted GitHub and configured Linear issue URLs are now resolved before workspace routing. Their issue details are supplied as bounded, untrusted routing context, with one shared 8-second fail-open lookup deadline. Trailing URL punctuation, including ellipses, is removed before lookup. GitHub routing now exposes the read-only issue tools required for this lookup.

Why this change was made

The router previously classified a task from the message and environment descriptions alone, even when a linked issue contained the information needed to choose the correct workspace.

Impact

Tasks started with a supported issue link can route using the linked issue's title and description. Punctuation from ordinary prose no longer prevents supported issue links from being recognized, while unavailable integrations and slow MCP responses continue routing without external context or extending the shared lookup budget.

[roomote-roomote]

No code issues found. See task

• packages/cloud-agents/src/server/router/external-issue-context.ts:149: The GitHub fallback shares the 8-second deadline, so it cannot extend routing latency beyond the advertised fail-open budget.
• packages/cloud-agents/src/server/router/external-issue-context.ts:33: Full trailing punctuation suffixes, including ellipses, are now removed without a regex performance risk.

_{Reviewed 838a2af}