v0.4.0

Added

• Parallel groups — concurrent role execution as a single compiled node. A
  workflow may declare parallel_groups (an array of arrays of role names, each
  group with >= 2 members). The members run concurrently
  (Promise.allSettled) as one compiled group node. They must not depend on each
  other (no sibling edges), cannot be kind: "scoring", and must share the same
  done successor — all validated, with a bad_parallel_group error on
  violation. If any member emits an interrupt/terminal event
  (error/question/waiting/needs_review) or fails hard, that event
  propagates and halts the run (highest-precedence wins) rather than being
  swallowed. run-manifest.json records the resolved_parallel_groups.
• Coverage ingestion — structured coverage from command roles. A command
  role's parser.coverage.format accepts c8-json, lcov, jest-json,
  cobertura, clover, or regex (the regex format requires a pct capture
  pattern). After the command exits, the runner reads the declared coverage file
  (path-confined, 4 MB cap) and fills evaluation.coverage as
  { overall_pct, by_command } — overall_pct is the arithmetic mean across
  contributing commands. An unknown format is rejected at validation
  (bad_command_spec).
• GitHub issue tracker backend. Set a tracker kind: "github" with
  owner/repo/token (plus an optional label, default maestro). It polls
  the REST API for labeled open issues and performs write-backs (comment, close,
  add-label), staying rate-limit aware.
• Inbound webhooks. POST /api/v1/webhook/:kind accepts github
  (HMAC-SHA256 signature via webhook_secret, verified timing-safe) and
  generic (bearer token via webhook_bearer_token, verified timing-safe).
  The body is capped at 1 MB. A webhook_template (with {{payload.path}}
  interpolation) renders the dispatched task title; the task is created against
  the configured workflow.
• Outbound lifecycle notifications. A notify config
  { on: [...events], url, format } (format: "slack" | "generic") fires
  best-effort POSTs on completed, halted, and approval_needed. It never
  throws and makes one attempt per event.
• Real mid-run cancellation. Cancelling a task now aborts the in-flight run
  at the next step boundary (via AbortController), sets status cancelled, and
  stamps cancelled_at in run-manifest.json. Previously cancellation only
  updated bookkeeping.

Changed

• Correctness scoring now blends coverage. When a workflow produces
  evaluation.coverage.overall_pct, correctness_score becomes the mean of
  pass_rate and overall_pct / 100 (was pass_rate alone). MIGRATION NOTE:
  workflows that opt into coverage parsing may see correctness_score drop even
  at a 100% pass rate — check any min_correctness gate. Workflows without
  coverage parsing are unaffected.
• require_distinct_reviewer is now default-on. When absent it behaves as
  true, but for this release it emits a WARNING (non_distinct_reviewer)
  rather than an error; it becomes a hard error in v0.5.0.

Deprecated

• experimental_per_edge_context graduated to the stable key
  per_edge_context. The old key still works but emits a deprecation warning —
  rename it.
• require_distinct_reviewer: false is deprecated. The check defaults on in
  v0.4.0 and becomes required in v0.5.0.

Notes

• Role Convention doc no longer pitches Maestro as the plan → execute → review pipeline. docs/role-convention.md now frames that flow as just the
  stock graph, consistent with the README's positioning. Documentation only — no
  behavior or API change.