## Summary
- Allow Cloud tenant issue identifiers with alphanumeric prefixes, such
as `PC1897-1`, to normalize as issue references.
- Resolve those identifiers through issue detail/update routes, active
run/live run polling, activity, costs, and `issueService.getById`.
- Keep UI issue-link parsing aligned so tenant links normalize back to
`/issues/<IDENTIFIER>`.
## Root Cause
Cloud tenant issue prefixes include digits from the stack-id hash. The
app-side route normalization still accepted only all-letter prefixes, so
`/api/issues/PC1897-1` skipped identifier lookup and fell through as a
non-UUID id.
## Verification
- `pnpm exec vitest run packages/shared/src/issue-references.test.ts
ui/src/lib/issue-reference.test.ts
server/src/__tests__/issue-identifier-routes.test.ts
server/src/__tests__/activity-routes.test.ts
server/src/__tests__/costs-service.test.ts
server/src/__tests__/agent-live-run-routes.test.ts
server/src/__tests__/issues-service.test.ts`
- `pnpm --filter @paperclipai/shared typecheck && pnpm --filter
@paperclipai/server typecheck`
- `git diff --check`
Co-authored-by: Paperclip <noreply@paperclip.ing>
Dotta