fix(web): raise UModel Explorer limit to 2000

[qiansheng91]

Summary

Raise the UModel Explorer query ceiling from 100 to 2000 elements so the graph, table, and sidebar statistics are no longer truncated for workspaces such as the reported 183-element model.

Motivation

The Explorer explicitly requested only 100 .umodel rows. Its type counts therefore represented the first 100 sorted elements rather than the complete workspace model, making 10 RunbookSet definitions appear as 4 in the UI.

Changes

• Web: request .umodel | sort name | limit 2000 from UModel Explorer.
• Web API client: rely on the SPL limit instead of sending a request-body limit above the OpenAPI maximum of 1000.
• Tests: add a Playwright regression test that captures the real Explorer request payload.
• Docs: align the English and Chinese Web UI API maps with the new request.

Test plan

• make build
• make test-service
• make guard
• make ci
• If user-facing: ran an end-to-end probe (all 18 Playwright tests passed; local Explorer graph/table rendered with no browser console warnings or errors)
• npx pnpm@9.15.9 --dir web run build
• git diff --check

Compatibility

No REST, SPL, MCP, or SDK schema changes. The Explorer keeps the 2000-row bound in the SPL query and omits the redundant request-body limit, preserving the existing OpenAPI maximum of 1000 for that optional field.

Out of scope

• Server-side pagination or loading workspaces with more than 2000 UModel elements.
• Changes to Apply/Upsert partial-success reporting.