feat: Add Bitwarden secrets and Anthropic distill support

[howailok1120]

Summary

This issue tracks a feature branch (feat/bitwarden-anthropic-distill) with the following changes:

• Bitwarden secret resolver (src/secret-resolver.ts) — resolves API keys from Bitwarden CLI or environment variables securely
• Anthropic LLM client (src/llm-client.ts) — adds a distill/extraction LLM client backed by the Anthropic API
• CLI entry point (cli.ts) — exposes distill functionality via command line
• Lesson extract worker updated — integrates secret resolution into examples/new-session-distill/worker/lesson-extract-worker.mjs
• Tests added — test/secret-resolver.test.mjs, test/llm-api-key-client.test.mjs, test/plugin-manifest-regression.mjs
• Plugin manifest & package updates — openclaw.plugin.json, package.json

Files changed (712 insertions, 34 deletions across 12 files)

 README.md
 cli.ts
 examples/new-session-distill/README.md
 examples/new-session-distill/worker/lesson-extract-worker.mjs
 index.ts
 openclaw.plugin.json
 package.json
 src/llm-client.ts
 src/secret-resolver.ts
 test/llm-api-key-client.test.mjs
 test/plugin-manifest-regression.mjs
 test/secret-resolver.test.mjs

Requesting

A maintainer with push access to this repo is needed to review and merge this work. Happy to provide the patch or branch if needed.

[AliceLJY]

感谢详细的 feature spec，两个特性都是用户高频需求 👍

实现已经在 PR #349 中，review 意见也已经留在那边了。后续讨论移到 PR 里，这个 issue 作为 tracking 保留。