release: v0.2.0 and clean public repository

[LoftyTao]

Release and repository hygiene

• bump the package and DSH manifest versions from 0.1.0 to 0.2.0
• point the Chinese and English installation commands to github:LoftyTao/dsh-ui-workbench#v0.2.0
• remove the internal AGENTS.md from Git while preserving it as a local ignored file
• ignore local agent state, dependencies, build output, coverage, temporary files, logs, and OS files
• keep source, tests, public documentation, CI, build configuration, and release scripts tracked

Validation

• node --test tests/*.test.mjs — 18 passed
• TypeScript no-emit check — passed
• build and verify:package — passed
• npm pack --dry-run --ignore-scripts — package dsh-ui-workbench@0.2.0, 23 files, no AGENTS.md
• pnpm check remains affected by the existing Windows temporary-file EPERM issue

The v0.2.0 tag remains immutable; this cleanup is carried by the follow-up commit on the release branch.