test(web-ui): restore OHOS E2E locators and strengthen model selector semantics

[azi44eo]

Summary

This PR improves Web UI E2E test locator coverage for OHOS automation. It restores missing navigation/skills locators and adds richer data-* attributes for chat model selection and settings model configuration flows, with matching documentation updates.

Changes

Restore OHOS E2E locators

• Sessions nav: add nav-session-menu-btn, nav-session-menu, nav-session-menu-rename, and nav-session-menu-delete, with data-session-id on menu-related nodes
• Skills scene: add tab locators (skills-tab-installed, skills-tab-discover) and panel locators (skills-installed-panel, skills-discover-panel), with data-skills-tab-active on tabs

Strengthen model locator semantics

• Chat ModelSelector: add data-option-kind, data-model-role, and data-provider-id for auto / primary / fast alias / ACP / normal model entries; alias entries also expose data-resolved-* fields
• Settings AIModelConfig: add structured locator metadata (data-option-kind, data-model-role, data-model-state, data-model-source, data-provider-id, data-config-id) for selectable options, selected drafts, saved models, and test-status nodes
• Docs: update docs/development/ui-testids.md and ui-testids-CN.md with the new attributes and locator guidance

Motivation

OHOS E2E tests need stable, unambiguous DOM selectors. Visible text and data-model-name alone are not reliable unique keys—especially for alias entries (auto, primary, fast) and multi-provider model lists.

Test plan

• Verify session menu actions (rename / delete) can be targeted via data-testid + data-session-id
• Verify Skills tab switching via skills-tab-* and panel visibility via skills-*-panel
• Verify chat model selector options can be distinguished by data-option-kind / data-model-role
• Verify settings model dropdown, draft rows, saved rows, and test-status nodes expose expected data-* attributes
• Confirm no product behavior changes (locator/metadata only)
• pnpm run type-check:web

Merge notes

• Fast-forward merge from main; no conflicts expected
• 6 files changed, +112 / -16 lines