spike: investigate Google Drive MCP OAuth flow failure

## Spike: Investigate Google Drive MCP OAuth Flow Failure

### Problem Statement
The Google Drive MCP server OAuth authentication consistently fails during setup. Users complete the OAuth flow in browser, get redirected to a "nothing found" page, but the terminal never realizes authentication completed.

### Current State
- OAuth flow reaches redirect page but terminal doesn't capture completion
- Currently an **accepted gap** in automation
- Users must manually intervene to complete authentication
- Violates Spilled Coffee Principle due to manual intervention requirement

### Investigation Goals
Determine the root cause of OAuth flow failure:

**Potential causes to investigate:**
- Port mismatch between redirect URI and listening port
- Network configuration issues with `--network host`
- OAuth callback handling in the MCP server
- Redirect URI configuration mismatch
- Browser security restrictions
- Docker networking issues

### Investigation Tasks

1. **Port Analysis**
- Determine what port the MCP server actually listens on during OAuth
- Check if `--network host` is appropriate or if specific port mapping needed
- Test with common OAuth ports (3000, 8080, 8000)

2. **OAuth Flow Tracing**
- Monitor network traffic during OAuth flow
- Check Docker logs during authentication attempt
- Verify redirect URI handling

3. **Configuration Validation**
- Compare Google Cloud Console redirect URI with actual server expectations
- Test different redirect URI configurations
- Validate OAuth scope requirements

4. **Alternative Approaches**
- Research how other MCP servers handle OAuth
- Consider manual token extraction as fallback
- Investigate if server supports different auth methods

### Success Criteria
- Identify root cause of OAuth flow failure
- Determine if fixable through configuration changes
- Document workaround if permanent fix not feasible
- Update setup script with findings

### Time Box
This is a research spike - limit investigation to avoid rabbit holes. If root cause not found quickly, document current workaround and move on.

### Context
Part of broader MCP automation effort following Spilled Coffee Principle. Currently this is the main gap preventing fully automated MCP server setup.

Start by locating the setup script and Docker configuration, then observe the MCP server port, Docker logs, redirect URI, and OAuth callback during a Google Drive authentication attempt. Done means identifying the root cause or documenting the workaround and updating the setup script with the findings.

Written by the indexing model from the issue text.