deploy_tee: fix the genesis-ceremony path + label disk-provisioning progress

[samlaf]

Summary

Fixes the operator-side seismic-tee-bootstrap genesis ceremony — which had
never actually run end-to-end against a real node — and labels the first-boot
disk-provisioning progress bar. Surfaced while bringing up the first
single-node TEE network to a live chain; with these changes (plus a companion
summit fix, see below) a node reaches a live chain (reth producing, summit
finalizing).

Changes

1. summit_client speaks JSON-RPC, not REST (fix)

summit's RPC is jsonrpsee (JSON-RPC 2.0, POST-only, camelCase methods — see
summit/rpc/src/api.rs), but summit_client did GET /<path> and
text/plain POSTs with snake_case paths. So getPublicKeys / sendGenesis
never worked against a real node.

Rewrote it as a JSON-RPC client: one _rpc(method, params) that POSTs the
envelope to the /summit base (nginx strips the prefix) and returns result,
using the real method names. Dropped the dead REST helpers and send_share
(no such endpoint, no caller). Added mocked tests for the envelope + error path.

2. Run the genesis binary from PATH with an explicit template (feat!)

genesis.py assumed a dev checkout — it shelled out to
~/summit/target/debug/genesis and ~/summit/example_genesis.toml.

Now it takes the genesis binary from PATH (the pattern summit uses for
reth), with a clear error if it's missing, and the template via
--summit-template. Dropped --code-path (its only job was locating
~/summit). Also logs the built genesis's path and each node it's sent to
before delivery (paths only, not contents), mirroring how configure logs
the config it POSTs.

Breaking: --summit-template is now required; --code-path is removed.

3. Label first-boot disk-provisioning progress (feat)

The progress bar showed bytes / % / eta but never said what it was doing.
Added an encrypting disk label and a one-time line when provisioning starts,
explaining it's the first-boot full-disk LUKS + dm-integrity wipe (one-time,
can take 1h+) so the long phase doesn't read as a hang.

Prereqs

seismic-tee-bootstrap genesis needs the genesis binary on PATH — built
from summit, e.g. cargo install --path node --bin genesis --locked (the
--locked matters; summit pins commonware via its lockfile).

Testing

• Unit tests (mocked, no network): summit_client request envelope + RPC-error
  path; existing manifest/configure/status suites still pass. ruff clean.
• Manually drove a single-node TEE network end-to-end to a live chain
  (cast block-number advancing) using these changes.

Follow-ups (not in this PR)

• eth_genesis_hash still needs a manual -g. summit's genesis template
  carries an eth_genesis_hash that must equal reth's actual genesis hash;
  today the operator passes it via -g. Proposed: have the ceremony
  auto-derive it from the node's own reth (eth_getBlockByNumber 0) and
  cross-check the cohort, removing the manual step.
• Companion summit fix (separate PR): the genesis binary defined its
  own genesis struct that had drifted from summit_types::Genesis and silently
  dropped required fields (validator_minimum_stake); fixed to use the
  canonical type. That PR also proposes moving genesis assembly into the node
  (sendGenesis taking template + validators) to retire the operator-side
  binary and the version-skew question entirely.
• genesis reads each node's summit pubkey once (no retry). A node that
  isn't ready yet fails the ceremony; retry-until-ready is a separate change.