Prune memos plugin package contents

[hijzy]

Summary

• Limit the memos local plugin npm package to runtime assets while keeping required dist and web/dist output.
• Exclude architecture/changelog/algorithm docs, nested README files, sourcemaps, pycache files, and compiled test output from the published package.
• Update Quick start docs to use install.sh instead of direct npm install, and remove the obsolete e2e probe script.

Test plan

• npx vitest run tests/unit/install/install-sh.test.ts
• npm pack --dry-run --json --ignore-scripts