feat(dsh): add DeepSeek Harness as a supported agent

[0x0101010]

What

Adds DeepSeek Harness (dsh) as a first-class supported agent, alongside hermes/openclaw:

• KNOWN_AGENTS: dsh entry (coding category) — skills at ~/.dsh/skills
• Default toolPaths: dsh: { skills: '.dsh/skills' } — no team config needed
• agent-version detection via dsh --version
• README / README.zh-CN feature matrix rows + usage-guide (EN/中文) agent-id lists, per the bilingual docs policy

Why

dsh's skill-filesystem provider (deepseek-harness packages/skill) natively scans user skill roots: ~/.dsh/skills (user-dsh, rank 400) and ~/.agents/skills (rank 500), discovering both <name>/SKILL.md bundles and flat .md files. Syncing into ~/.dsh/skills gives dsh sessions the team harness with zero dsh-side config — the standard integration pattern used for the other agents.

dsh also ships Claude Code / Codex hook bridges, but skills-sync is the stable, non-invasive surface; hooks/env/MCP can follow once the dsh-side config surface stabilizes.

Verification (real CLI, end-to-end against a self-hosted GitLab 18.7)

$ npm run build                       # tsup, success
$ npx tsc --noEmit                    # clean
$ npx vitest run                      # 2183 passed; 2 pre-existing failures in builtin-agents.test.ts (fail on main too, unrelated)
$ node dist/index.js init root/teamai-harness --scope user --agent dsh   # dsh accepted as agent id
$ node dist/index.js pull             # → 'Synced 331 skills' → ~/.dsh/skills (331 dirs)

Removing the custom toolPaths.dsh from the team repo's teamai.yaml and re-pulling confirmed the built-in default drives the sync (team config no longer required for dsh).

Test plan checklist per CLAUDE.md — build ✅, real CLI e2e ✅, docs updated in both languages ✅.

[jeff-r2026]

LGTM