Problem
The journalism-investigation plugin has 11 MCP tools but no CLI commands. AI agents can query via MCP; humans have no `pyrite investigation` subcommands and must use raw `pyrite search` or `pyrite get`.
Scope
Add a Typer sub-app registered via the plugin get_cli_commands() method. Commands should mirror the read-tier MCP tools:
`pyrite investigation timeline [--from DATE] [--to DATE] [--actor NAME] [--type TYPE] [--min-importance N] -k KB`
`pyrite investigation entities [--type TYPE] [--jurisdiction J] [--min-importance N] -k KB`
`pyrite investigation sources [--reliability R] [--classification C] -k KB`
`pyrite investigation claims [--status S] [--confidence C] -k KB`
`pyrite investigation evidence-chain CLAIM_ID -k KB`
`pyrite investigation network ENTRY_ID -k KB`Output should be human-readable tables (rich or tabulate), with --json flag for machine output.
Acceptance Criteria
All 6 commands work and produce formatted output
--json flag outputs raw JSON on all commands
Commands share the same filter logic as MCP handlers (no duplication -- extract shared query functions)
`pyrite investigation --help` shows all subcommands