Adds docs/superpowers/specs/2026-06-30-pluggable-mcp-design.md describing
a refactor of main.py: McpService dataclass moves to common/mcp_service.py
alongside BUILTIN_SERVICES list and discover_and_filter() helper. Each
service package gets a service.py exporting a SERVICE McpService instance.
Deployments opt in/out via MCP_SERVICES env whitelist (unset = all).
Branch: feat/files-mcp (continues from file-MCP service work; same branch,
not pushed; can be split into separate PRs later)
Backward compat: 0 existing tools / tests / dependencies changed;
unsetting MCP_SERVICES reproduces today's behavior exactly.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Adds docs/superpowers/specs/2026-06-30-files-mcp-design.md describing a
sibling FastAPI sub-app (mount: /files-mcp) that exposes 9 file operations
(create/read/update/delete/list_dir/stat/search/move/copy) over fastapi-mcp,
sandboxed to FILES_MCP_ROOT with utf-8 text only and atomic writes.
Branch: feat/files-mcp
Mount path: /files-mcp
New package: files_mcp/
Backward compat: 0 existing tools / tests / dependencies changed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
