fix: preserve library skills during adopt

[travelhawk]

Summary

• Fixes agentpm adopt <name> so re-adopting an already canonical library skill links it into selected agents instead of replacing the library copy with a self-link.
• Restores the documented agentpm push --all CLI flag and updates quickstart JSON recipes to be safe for non-interactive agent use.
• Adds --target, --scope, and --path filters to agentpm remove and agentpm skills remove so agents can remove one duplicate install without a TTY picker.
• Adds a README prompt for AI agents to install and operate AgentPM without TTY menus, plus 0.9.2 changelog/version bookkeeping.

Validation

• pnpm lint
• pnpm typecheck
• pnpm test
• pnpm build
• pnpm smoke if user-facing CLI behavior changed
• Manual double-adopt repro confirmed the canonical SKILL.md survives and new target is linked
• Manual agentpm --version, agentpm quickstart --json, agentpm push --help, and agentpm remove --help

Release Impact

• none
• patch
• minor
• major

Notes

• Version is bumped to 0.9.2 because 0.9.1 has already been published.
• The remove fix keeps the interactive picker for humans, but gives agents deterministic filters for duplicate install names.
• The adopt fix is intentionally conservative: unmanaged target directories are still skipped unless explicitly confirmed, and the new self-link guard prevents this class of data loss at the filesystem helper boundary.