feat(notebooklm): add read commands and compatibility layer

[muqiao215]

Summary

This PR adds the first stable NotebookLM milestone for opencli, focused on read commands and a compatibility layer aligned with the existing notebooklm-cdp-cli command style.

Included

• NotebookLM compatibility aliases/wrappers without changing opencli's flat command model
• Stable notebook binding for read commands
• Read commands:
  • status
  • list
  • current
  • get
  • metadata
  • use
  • source-list
  • source-get
  • source-fulltext
  • source-guide
  • history
  • note-list
  • notes-get
  • summary
• Improved source type parsing for pdf / web / pasted-text / youtube
• RPC-backed source fulltext and guide support

Deliberately Not Included

• ask
• source-add-*
• notes-save
• generate/*
• download/*
• artifact/*
• nested command-tree refactor

Why this scope

The goal of this PR is to land a solid read-surface milestone first, with live validation on the existing browser-bridge path, before moving into write operations and long-running jobs.

Verification

• npx vitest run src\\clis\\notebooklm\\source-guide.test.ts src\\clis\\notebooklm\\source-fulltext.test.ts src\\clis\\notebooklm\\summary.test.ts src\\clis\\notebooklm\\notes-get.test.ts src\\clis\\notebooklm\\compat.test.ts --reporter=dot
• npx tsc --noEmit
• live smoke runs against real NotebookLM sessions for:
  • notebooklm status
  • notebooklm get
  • notebooklm source-list
  • notebooklm history
  • notebooklm metadata
  • notebooklm source-get
  • notebooklm source-fulltext
  • notebooklm source-guide