[BUG] `apm install --global` skips MCP server installation for all runtimes

[sergio-sisternes-epam]

Describe the bug

When installing APM packages with --global (-g), MCP server entries are never written to any runtime config file. The install command unconditionally sets should_install_mcp = False at user scope, assuming all MCP configs are workspace-scoped:

# install.py:743-749
# MCP servers are workspace-scoped (.vscode/mcp.json); skip at user scope
if scope is InstallScope.USER:
    should_install_mcp = False

This assumption is incorrect. Multiple supported runtimes have global/user-scoped config paths:

Runtime	Global config path	Documentation
Copilot CLI	~/.copilot/mcp-config.json	GitHub docs
Codex CLI	~/.codex/config.toml	Global by design
VS Code	User profile mcp.json	VS Code docs -- "Servers configured here are available across all your workspaces"

The same guard also silences --trust-transitive-mcp at global scope -- transitive MCP collection (install.py:839) is gated behind should_install_mcp, so the flag becomes a silent no-op.

To Reproduce

1. Run apm install -g some-package-with-mcp
2. Check ~/.copilot/mcp-config.json (or other global runtime config)
3. No MCP servers are present

With --verbose, the log shows: "MCP servers skipped at user scope (workspace-scoped concept)"

Expected behavior

MCP servers from the installed package should be written to the global config path of each applicable runtime (e.g. ~/.copilot/mcp-config.json for Copilot CLI). --trust-transitive-mcp should also work at global scope.

Environment (please complete the following information):

• OS: All
• Python Version: 3.12
• APM Version: current main

Logs

At --verbose level: "MCP servers skipped at user scope (workspace-scoped concept)"

Additional context

Root cause chain:

1. install.py:744-745 -- blanket should_install_mcp = False for InstallScope.USER
2. install.py:839 -- transitive MCP collection gated behind the same flag, making --trust-transitive-mcp -g a silent no-op
3. MCPIntegrator.install() (mcp_integrator.py:798-807) has no scope parameter -- no mechanism to tell the integrator which scope is active
4. No per-adapter scope classification exists to distinguish workspace-only from global-capable adapters

Suggested fix direction:

• Add scope awareness to MCPClientAdapter (e.g. supports_user_scope -> bool)
• Pass scope through to MCPIntegrator.install()
• At user scope, install to global-capable runtimes; skip workspace-only adapters
• For VS Code, add support for the user profile mcp.json path alongside the existing workspace path