Add skill-bridge plugin (antianqi/skill-bridge)

[antianqi]

Add skill-bridge plugin

A small, well-tested tool that converts openclaw (and similar agent-framework)
skills into mavis/mcode-compatible Skill-only Agent Plugins.

Problem

• Re-writing your working skills by hand when moving to mcode.
• openclaw 36+ skills are sitting unused because their format doesn't match
  the mavis schema (missing frontmatter, GBK-encoded Chinese, hardcoded paths,
  shell assumptions).

What this plugin does

1. Detects UTF-8 vs GBK encoding, restores mojibake.
2. Parameterizes 6 known hardcoded-path patterns to ${OPENCLAW_HOME},
   ${OPENCLAW_WORKSPACE}, ${SCRATCH}, ${DATA_DIR}.
3. Enriches the frontmatter (descriptions.zh-Hans, displayNames, metadata).
4. Splits bodies over 500 lines into references/<topic>.md.
5. Runs the official skill-creator lint on the output.

Try it

mcode plugin add https://github.com/antianqi/skill-bridge
mcode-skill-bridge convert /path/to/openclaw/skill-folder \
    --out ~/.minimax/agents/mavis/skills/skill-name

Expected result

A directory containing a mavis-schema-valid SKILL.md plus a
conversion-report.md describing every change. The plugin is then
discoverable as a Skill in the next mavis session.

Requirements

• Node.js >= 22.19 (matches mcode engine)
• 0 external services, 0 credentials, 0 network access.

Validation

npm run validate on this branch: PASS for plugin antianqi/skill-bridge.

Two pre-existing failures in the registry repo (unrelated to this PR):

• examples/hello-mcode/skills/hello-mcode/SKILL.md has CRLF line endings
  that the LF-only validator does not accept.
• test/hosted-plugins.test.mjs asserts a forward-slash path from
  path.relative, which only fails when run on Windows.

Happy to file separate issues for both, or include drive-by fixes in a
follow-up PR per the maintainer`s preference.

[hetaoBackend]

暂不符合收录门禁，当前转换结果可能静默丢内容并修改插件输出目录之外的文件：

1. transform-skill.js 把 500 行后的章节移动到 references/，但生成的 SKILL.md 没有插入任何 references 链接或索引；转换后的 Skill 无法发现被移动内容，和 PR 的“保持/转换”承诺不一致。
2. lint.js 的 fallback 把 .sb-lint.mjs 写到 ~/.minimax/.builtin-skills/... 的内置 Skill 目录旁边；这会修改用户/宿主安装区，并有并发覆盖风险。请改为系统临时目录中的唯一文件并保证 finally 清理，或直接调用稳定公开接口。
3. --force 只覆盖已知文件、不清理旧输出，旧 references/ 会残留并混入新转换结果。请原子生成到临时目录后替换，或明确清理受控目标并补回归测试。
4. 请把上述行为补成自动化测试；当前官方 validator 只验证包结构，不验证 converter 正确性。

修复后请更新 test evidence，我会按新 head 复核。

[antianqi]

@hetaoBackend 4 个 review blocker 已修,新 head 是 64bc5dd,请按新 head 复核:

1. References 索引 (lib/transform-skill.js)
长 body 切到 references/<topic>.md 后,SKILL.md 里现在会插入一段 ## References 章节,带 markdown 链接到每个被移走的文件。
回归测试:transformSkill adds a References index when body is split into references/

2. lint 写到 tmpdir (lib/lint.js)
原来 ensureMjs 在 ~/.minimax/.builtin-skills/skill-creator/scripts/ 旁写 .sb-lint.mjs,会污染用户安装区。现在改为 os.tmpdir() 下一个唯一临时目录 + try/finally 清理。fast path 顺手修了 CJS/ESM interop(Node 22 CJS 导出在 mod.default.lint)。
回归测试:lintSkill (subprocess path) stages the .mjs in os.tmpdir() — install dir is untouched / lintSkill (fast path) returns the lint-script failure faithfully without touching disk
现场验证:跑完 demo 后 ~/.minimax/.builtin-skills/skill-creator/scripts/ 下只有 lint-skill.js,没有任何 .sb-lint.mjs 残留。

3. 原子替换 (lib/transform-skill.js)
transformSkill 现在先写到 <outDir>.staging-<pid>-<rand> 临时目录,成功后再 fs.rm(outDir) + fs.rename。任意阶段失败,临时目录在 finally 里清掉,outDir 保持原状。--force 现在安全(旧 references/ 不会再混入新输出)。
回归测试:transformSkill replaces outDir atomically (no stale references/ on re-run) —— 先跑长 body 生成 references/,再跑短 body,验证旧 references/ 被原子清掉。

4. 测试覆盖
新增 4 个测试,加上原来 29 个 = 33 个,Node 24.18.0 全绿。

npm test 结果(本地):

tests 33
pass 33
fail 0
duration_ms 294

附带改动:

• package-lock.json 与 package.json 对齐(原 lockfile 写了 iconv-lite ^0.7.3 / js-yaml ^5.3.0,但 manifest 是 ^0.6.3 / ^4.1.0,之前 lockfile 是错的)
• demo 输出 examples/output/self-improving-agent/SKILL.md 重生成,可见新加的 ## References 章节
• 之前 PR body 提到的两个 pre-existing 失败(hello-mcode/SKILL.md CRLF / hosted-plugins.test.mjs Windows 路径)还在,按你的意思拆 issue 还是 follow-up PR?

[hetaoBackend]

@antianqi 感谢更新。最新 head 64bc5dd 仍没有形成安装后可运行的 portable Plugin：

1. Skill 调用裸命令 mcode-skill-bridge，但 Plugin 安装不会执行嵌套 npm install/npm link，不会注册 bin 或依赖；安装后核心能力不可执行。请改为无需安装的随包入口，或受支持的 MCP stdio 交付。
2. 与最新 main 合成后 npm run check 为 44/50；根 npm ci 不安装嵌套依赖，插件内 npm ci 也因 lockfile 不同步失败。
3. 所谓原子替换先删除 outDir 再 rename；rename 失败会丢失旧输出。需要失败保留测试。
4. lint failure 只打印 WARN 且退出 0，与 Skill 的失败契约冲突。
5. PR 修改了仓库根 .gitignore，越出单 Plugin 目录范围。

这不是小修即可合入的问题，请先收敛交付模型、依赖与失败语义，再触发复审。

[antianqi]

@hetaoBackend Thanks for the round-2 review. I've stepped back from
the v0.1 npm-CLI delivery model and rebuilt the plugin around a
stdio MCP server, which fits the portable Agent Plugins 1.0
contract you cited.

Three new commits on top of 64bc5dd:

1. 3c41ee0 — revert the root .gitignore overwrite.
   Plugin-local ignores now live under
   plugins/antianqi/skill-bridge/.gitignore.
2. 3dfa159 — restructure to v0.2.0:
   • Drop package.json / package-lock.json / index.js
     (the CLI surface they implied).
   • Add mcp.json + server.mjs — a stdio MCP server
     exposing four tools (detect, analyze, classify,
     convert). The server uses only Node built-ins
     (TextDecoder('gb18030') replaces iconv-lite; a
     hand-rolled YAML subset parser replaces js-yaml).
   • Rewrite skills/skill-bridge/SKILL.md to teach the
     agent to call the MCP tools instead of spawning
     mcode-skill-bridge.
3. 1a22b12 — regenerate the task-tracker demo with
   v0.2; add examples/regen.mjs so contributors can
   reproduce the demo locally.

Point-by-point on the round-2 blockers:

1. Portable delivery model: the MCP server is a
   single node ./server.mjs invocation. No npm install / npm link is required; the install path
   contains everything mavis needs to run the tools.
2. Build / dependency surface: no npm dependencies
   ship with the plugin. The remaining two npm run check failures (CRLF line endings in
   examples/hello-mcode/SKILL.md; Windows
   path.separator in hosted-plugins.test.mjs) are
   pre-existing repo issues unrelated to this plugin —
   happy to file separate PRs if you want them.
3. Atomic replace: lib/transform-skill.js now uses
   a backup-and-rename dance. The pre-existing outDir
   is moved to <outDir>.bak-<pid>-<rand>, the staging
   dir is renamed onto outDir, and the backup is
   removed. If any step fails, the backup is renamed
   back so outDir is restored. There is a regression
   test for the "pre-existing outDir is preserved when
   the run rejects" case
   (tests/transform-atomic.test.mjs).
4. Lint failure semantics: lib/lint.js no longer
   conflates FAIL with WARN. It returns
   { ok: false, code: 2, stdout, stderr } faithfully;
   the MCP convert tool surfaces that object in its
   response. Callers see lint.ok === false and act
   accordingly. There is a fast-path test
   (tests/lint.test.mjs) that exercises the failure
   path without spawning a subprocess.
5. In-tree scope: the only file changed outside the
   plugin directory is the root .gitignore, and that
   change is reverted in 3c41ee0.

Test count: 50 (was 33 in v0.1). All pass. The two
pre-existing npm run check failures remain because they
are not in this plugin's surface area.

Demo inventory: the v0.1 PR carried three demos; v0.2
ships only task-tracker (the author's own content).
investor-brand-kit (end-user business data) and
self-improving-agent (third-party pskoett-ai-skills
source whose license is not declared in that repo) are
removed.