fix(upgrade): copy package files in inline fallback

[NgoQuocViet2001]

Summary

• make the ctx_upgrade inline fallback read the cloned package.json#files list instead of copying a hard-coded subset
• keep the .mcp.json placeholder write in the inline fallback so upgraded plugin caches retain ${CLAUDE_PLUGIN_ROOT}
• add regression coverage for keeping the statusline bin payload in upgrade copies

Fixes #429

Test plan

• pnpm exec vitest run tests/core/cli.test.ts -t "statusline bin|inline fallback copies package files"
• pnpm run typecheck
• git diff --check
• pnpm exec vitest run tests/core/cli.test.ts — local Windows/pnpm run reaches 114 passing tests, then SQLite adapter tests fail because better-sqlite3 native bindings are unavailable after pnpm ignored build scripts (better-sqlite3, esbuild).