RFC-0001 Rev 8: simplify CLI client surface (remove use, hide list, delete owns teardown)

[saadqbal]

Tracks the Rev 8 amendment (docs/rfcs/0001-cli-auth-and-client-provisioning.md §15), prototyped in #136.

Direction: one machine = one client = one cluster.

• client use + the D3 picker removed (nothing to select).
• client list hidden (kept only for the installer's client#303 pre-flight).
• client create stays provision-only; the one-line installer remains the create front door (CLI never bootstraps the cluster).
• client delete owns the inverse teardown (deprovision + helm uninstall + local cluster delete) — realizes R12.

Supersedes the §7.3 selected-vs-connected picker work (closed #133; its cluster info binding + explain cleanup were folded into #136).

Acceptance gate: the amendment must be accepted (owner sign-off) before #136 flips draft→ready. See the two verification follow-ups linked below.

[LukasWodka]

Owner sign-off: the §15 amendment is ACCEPTED. (Lukas — posted from his Claude session after a full alignment review, 2026-07-07.)

Checked against every locked decision and nothing conflicts — it is the current logic:

• A1/A2 (remove use, hide list): follows directly from the one-machine=one-client invariant (Q5 + the cluster_id anchor) — nothing to select. Consistent with today's board cleanup (RFC-0001 · P1 · cli — §7.3 "selected is not connected": bind data commands to the active client + show connected state in client list #128 closed as superseded).
• A3 (installer = create front door, CLI never bootstraps): exactly the installer-UX-v2 stance (backend#992) — reaffirmed, not changed.
• A4 (client delete owns teardown = R12): accepted; RFC-0001 · P2 · cli — offboarding: client delete + --uninstall (R12; the k3d rebuild-orphan cure) #129 is closed as absorbed into this, with e2e-verify tracebloc delete offboard teardown against a throwaway k3d cluster #140 (e2e teardown verify) + Confirm installer client#303 pre-flight still works with a hidden client list #141 (client#303 pre-flight vs hidden list) as the acceptance follow-ups — both already filed.
• §15.3 keeps the §7.3 data/cluster-info binding that shipped in cli#142 — confirmed live on develop.

One naming nit for the final text: the section header says "Amendment (Rev 9)" while this ticket and the body callouts say Rev 8 — unify before merging the doc. @saadqbal: unblocked — #136 can flip draft→ready (or re-open on a fresh branch off develop, which now carries #142).

[LukasWodka]

Shipped in #160 (merged to develop). The full surface is in code: client use removed, client list hidden (internal/cli/client.go:100), and the top-level tracebloc delete owns teardown (internal/cli/root.go:98 + delete.go).

Note: the title says Rev 8, but the accepted amendment is Rev 9 (§7.10, committed via #157) — same substance, superseded naming. Remaining verification is separately tracked in #140 (e2e teardown) and #141 (installer pre-flight vs hidden list), so closing this drops no work. Closing as done.