migrate to zkBoost v0.9

[chetanyb]

Migrate to zkBoost v0.9

Adapts proofessoor to zkBoost's v0.9 API and wire types, and closes the
missed-failure reconciliation gap. Stacked on #3.

Changes

• v0.9 protocol: requests and verifications now send SSZ
  ProofRequestBody and ProofVerificationBody payloads, with proof types
  included in the body instead of query parameters. The beacon-block to
  NewPayloadRequest conversion is explicit and protected by a golden
  request-root test.
• ChainConfig derived from the beacon node: the per-request ChainConfig
  is resolved from /eth/v1/config/spec and /eth/v1/beacon/genesis, fetched
  once at startup. The schedule includes BPO blob entries and selects the
  active fork from the payload timestamp. Verification resolves the same
  configuration from the recorded slot, avoiding another config file.
• Failure replay reconciliation: replayed proof_failure events are applied
  after reconnect. Failures are buffered through the probe window so a
  completion observed in the same window wins. Tests cover the stale-failure
  race and terminal metric behavior.
• OTel in shipped images: Docker and release CI builds include the otel
  feature, while export remains opt-in through
  OTEL_EXPORTER_OTLP_ENDPOINT. Outbound W3C trace context propagates into
  zkBoost.
• zkBoost crates are pinned to an exact upstream eth-act revision containing
  add trace contex, el headers and failure replay eth-act/zkboost#70.

Breaking

• Requires a zkBoost v0.9-compatible server. A v0.8 server cannot parse the new
  SSZ request body.
• The Beacon endpoint must expose /eth/v1/config/spec and
  /eth/v1/beacon/genesis.
• Version bumped to 0.3.0 accordingly.