v0.5.0

Minor release. Aligns the parser with the community cluster's move
to the main Agave repository (Alpenglow: 200 ms blocks, ~250 ms
finalization) and adds two visible features in the TUI: a
selected-slot detail card in the Slots tab and a top-3 packed
blocks leaderboard in the Live tab's chain widget.

Changed

• Parser format alignment. Upstream Alpenglow refactored the
  Block type from a (Slot, Hash) tuple to struct Block { slot, block_id }; the Debug output that abracadabra scrapes changed
  shape for six event categories (Block, Block Notarized,
  Block notar-fallback, Finalized, Parent ready, Produce window). All six parsers now consume the new struct form. Old
  tuple-format logs are no longer parseable — block, notarize,
  and finalize events will silently drop. This is intentional: the
  community cluster restarted onto the Alpenglow build, so historic
  tuple logs from the pre-move chain are no longer operationally
  relevant. Includes a regression guard (DRIFT-01) that
  include_str!s a slab of real log lines and asserts every event
  category yields at least one parse — future upstream drifts fire
  on the first cargo test after a rebase.
• Latency band recalibration. Old thresholds (assembly 500/600,
  lifecycle 600/1000 ms) were tuned for the pre-Alpenglow slot
  cadence; under Alpenglow every value coloured green (p99 lifecycle
  = 495 ms, well below the old warn line). Recalibrated to
  assembly 250/300 ms and lifecycle 380/500 ms, backed by empirical
  p50/p95/p99 measurements on a 3 h reference log. The middle band
  now uses cyan (accent_style) instead of yellow via a new
  band_latency_soft helper — yellow reads too harsh for the small
  window between "healthy" and "degraded" under the new cadence.
  Skip-rate and canonical-skip bands keep their yellow warning
  semantics.

Added

• Selected-slot detail card in the Slots tab. The reference
  panel now shows a compact per-slot timeline for the cursor-focused
  row: block id (short), signature count, and every captured event
  timestamp as a delta from an anchor. Anchor labels name the event
  class ((start) for first_shred, (emit) for our own leader
  slots, (replay) for repair-fetched slots, (anchor) for
  skipped-slot fallbacks) so the reader can tell what the deltas
  span without consulting the footer. Every value is a direct
  log-event timestamp — no inference.
• sigs column in the Slots table — signature_count from
  the bank frozen log line. Empty for slots the local node did
  not bank (repair-fetched, gossip-observed).
• Top-3 packed blocks leaderboard in the chain pane (Live tab).
  Small right-side panel listing the three signature-heaviest
  blocks observed since the pane started. Fork-safe (first-wins on
  the underlying signature_count), zero-sig blocks excluded,
  session-long (no reset). Layout mirrors the tx stream on the
  right side of the bucket with a one-column border gap.

Fixed

• Slots detail card path tags. The (slow-path) suffix on
  notar_fallback rows was unconditional, but the vast majority of
  BlockNotarFallback events are benign auto-emitted companions of
  successful notarize certs — on any fast-finalized slot the card
  printed notar_fallback (slow-path) immediately followed by
  finalized (fast-path), contradicting itself. Now gated on the
  row's actual path.
• Slots detail card anchor note. The footer text branched on
  we_are_leader and claimed t0 = our local replay complete for
  every non-leader slot — but for the majority of observed slots
  the anchor is first_shred_at (shred receipt), not replay. The
  note now branches on the actual anchor event and describes each
  case correctly.
• Latency-band legend labels now use < / ≥ to match the
  underlying band function's inequality (previously ≤ / > — a
  one-off at exact boundaries).