docs(antigravity): expand installation guide with power-user remote t…

[cody-small]

…oolsets and Grok-style full integration examples

Summary

Why

Fixes #2529

What changed

MCP impact

• No tool or API changes
• Tool schema or behavior changed
• New tool added

Prompts tested (tool changes only)

Security / limits

• No security or limits impact
• Auth / permissions considered
• Data exposure, filtering, or token/size limits considered

Tool renaming

• I am renaming tools as part of this PR (e.g. a part of a consolidation effort)
  • I have added the new tool aliases in deprecated_tool_aliases.go
• I am not renaming tools as part of this PR

Note: if you're renaming tools, you must add the tool aliases. For more information on how to do so, please refer to the official docs.

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

• Not needed
• Updated (README / docs / examples)

[SamMorrowDrums]

Closing — this PR's framing ("Grok parity") and the marketing-style description don't reflect a concrete bug or gap we'd want to address this way, and the change itself contains issues (e.g., a Windows-style backslash path on a non-Windows code path). If there's a specific concrete improvement underneath this, happy to look at a focused PR. Thanks!