Align .claude/ tooling with the modular FastMCP architecture

[AndreaV-Lsi]

Problem

The .claude/ tooling still describes the legacy single-file server
(openproject-mcp.py with list_tools() / call_tool() dispatch). The real code is modular
FastMCP: tools self-register via @mcp.tool in src/tools/*.py, with HTTP in src/client.py
and the server assembled in src/server.py. Anyone following the .claude commands today is led to
the wrong architecture.

Scope — files to change

• .claude/config.json
  • primaryFiles lists openproject-mcp.py → should point at openproject-mcp-fastmcp.py and
    src/tools/*.py / src/client.py.
  • runCommand = uv run python openproject-mcp.py → uv run python openproject-mcp-fastmcp.py.
  • alwaysInclude references a non-existent .env.example → actual file is env_example.txt
    (see also the README fixups issue).
• .claude/commands/add-tool.md — rewrite steps 2–4 ("add to list_tools()", "implement in
  call_tool()") to the real pattern: add a @mcp.tool function in the right
  src/tools/<domain>.py, a Pydantic input model (subclassing CoercibleModel where wrapped), and
  a client method in src/client.py. Drop "single-file architecture".
• .claude/commands/review-tool.md — replace list_tools() / call_tool() language with the
  decorator/module pattern.

Out of scope

• Any runtime Python change.
• Rewriting the .claude/README.md wholesale.

Acceptance criteria

• The .claude config and commands describe steps that actually work against the current src/
  layout; no references to openproject-mcp.py, list_tools(), or call_tool() remain.

Type: docs/tooling, low risk. Label: backlog.