M7d follow-ups — remote TLS/auth polish

Context

M7d (#53) shipped opt-in TLS + bearer-token auth + TOFU for the remote daemon. These are the deferred minors from its review and threat model (docs/remote-tls.md, docs/superpowers/specs/2026-08-03-clowder-m7d-remote-tls-auth-design.md). None block use; all are polish/hardening.

Note: the "exposure warning still says NO authentication under TLS" minor was already fixed in the cleanup batch (#54).

Follow-ups

• Token logged in cleartext at info-level (crates/clowder-daemon/src/main.rs) — the bearer token is printed to the daemon log on startup so the operator can copy it, but it then lands in any log aggregation. Consider redacting from the log and pointing operators at clowder remote-token (which reads the state-dir file) instead, or writing it to a 0600 file only.
• Credential rotation is all-or-nothing (crates/clowder-daemon/src/remote_tls.rs::load_or_generate) — it only takes the "load" path when all three files (remote-cert.pem, remote-key.pem, remote-token) exist; deleting any one regenerates all three, so "rotate the token" silently also rotates the cert and breaks every client's TOFU pin. Consider independent token rotation (e.g. clowder remote-token --rotate that regenerates only the token) and/or an explicit --rotate-cert.

Larger deferred items (design-only in the M7d spec)

• mTLS / client certificates — channel-bound client auth instead of a bearer token.
• QUIC transport (quinn) — if roaming/mux ever matters (M7 deliberately deferred this; TCP+TLS is adequate for a terminal).
• Configured-fingerprint pin / pairing UX — an alternative to TOFU that closes the first-connect window (a single pasted "pairing string" of fingerprint + token).
• macOS Keychain storage for the client token (currently config/env only; the Rust forwarder would need security-framework).

Start with docs/remote-tls.md and the M7d design spec, then inspect crates/clowder-daemon/src/main.rs and remote_tls.rs::load_or_generate. Focus on the two concrete follow-ups before the design-only items: prevent startup credentials from being exposed in logs and ensure token rotation does not invalidate the certificate or TOFU pin. No tests are named in the issue, so confirm the acceptance criteria with maintainers.