feat(cli): accept basou portfolio list and redirect --check

[takashi-matsuyama]

Why

Follow-up polish on basou portfolio (#173). The core listing shipped, but two natural agent spellings still errored — ironic for a change whose goal is removing foot-guns:

• basou portfolio list → error: too many arguments (an agent reaching for a list sub-verb).
• basou portfolio --check → error: unknown option '--check' (--check is a basou view flag; the old memory shorthand reached for it).

What

• basou portfolio list now lists — an alias for the bare command. Any other action word is rejected with a pointer.
• basou portfolio --check prints a pointer to basou view --portfolio --check (where the redundancy/footprint preflight lives) and exits 1. It still never runs the preflight — the scope boundary vs basou view --check (a fixed constraint from feat(cli): add read-only basou portfolio listing command #173's review) holds; --check is declared only to turn the mistake into a signpost.

Verified (local)

basou portfolio             -> exit 0 (list)
basou portfolio list        -> exit 0 (list)
basou portfolio --json      -> exit 0
basou portfolio list --json -> exit 0 (12 workspaces)
basou portfolio --check     -> exit 1 + "Run `basou view --portfolio --check` ..."
basou portfolio bogus       -> exit 1 + "Unknown portfolio action 'bogus' ..."
basou portfolio list extra  -> exit 1 (commander: too many arguments)

Misuse branches exit 1 (matching commander's own unknown-option exit and the 62 other exit-1 sites in the CLI; exit codes are part of the 1.0 compat contract), not a novel code. cli typecheck / biome / lint:lang / 996 cli tests green; new runPortfolioCommand dispatcher tests cover the list alias, the --check redirect (exit 1, never reads config or lists), and unknown-action rejection.

Review note

The delegated adversarial reviewer was cut off mid-run by a session limit, so this went through a self-review + empirical edge-case verification instead (bare / list / --json / list --json / --check / bogus / list extra / --check+list precedence). That surfaced and fixed one real issue: the misuse branches originally used a novel exitCode 2, now normalized to 1 for consistency with the rest of the CLI and the compat contract.

Scope

Additive; no change to the --json contract or any other command. Bundles with #173 into the next release (v0.35.0).

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