[FEATURE] GAP-096: VS Code workspaceStorage MCP profile discovery

[hello-args]

Summary

Discover MCP configs under VS Code workspaceStorage and user profiles (GAP-096).

Problem

GAP-096 is Missing (P0). Inventory only checks well-known static paths in client_registry.py.

Related gap (validated 2026-06-17): --config-path on a VS Code settings.json file that uses the mcp.servers shape returns zero entries because parse_config_file("user", path) only applies the VS Code extractor when client == "vscode". Explicit --config-path hardcodes client label "user". Standard mcpServers JSON works; VS Code nested settings format does not.

Expected Behavior

1. Expand auto-discovery to workspaceStorage / profiles per plan.
2. When --config-path points at a VS Code settings file, detect mcp.servers (and other known shapes) from payload structure, not only from client registry label.

Evidence

• src/mcts/inventory/discoverers.py — _extract_mcp_servers, parse_config_file
• src/mcts/inventory/runner.py — config_path branch uses parse_config_file("user", path)

References

• GAP-096 — feature expansion plan, docs/scanning/inventory.md planned gaps
• [SECURITY] mcts inventory reads local MCP configs without consent gate #87 / PR feat(inventory): add privacy controls for config discovery (#87) #279 — --config-path shipped

Acceptance Criteria

• workspaceStorage / profile discovery paths added and tested
• --config-path parses VS Code mcp.servers settings files
• Documented in docs/scanning/inventory.md