MCP Apps: timesheets create (entry form with project, iteration, category pickers)

[jernejk]

Part of MCP Apps (#78). Create.

A form to log an entry: client search (search_clients), project (get_projects_for_client, sentinel row already filtered), iteration when the project uses them (list_iterations), category, date, start/end or hours, deducted minutes, location, note. Submits through create_timesheet, which runs the shared TimesheetCreateService, so the no-active-rate outcome shows the tp rate create recovery instead of creating a rate. Shows the saved entry returned by the tool.

Depends on the deducted-minutes argument being added to create_timesheet (0.4.0 schema change) for full parity with tp ts create --less.