v0.7.9 — planner producer-dependency fix (#182)

[0.7.9] - 2026-07-14

Planning — validator enforces the producer-dependency contract (fail-fast)

• validate_plan_doc.py now errors when a lane consumes an interface provided by
  another in-plan lane it does not depend on directly (a new (O) check). Previously
  the plan validator passed such a plan (check F only traced that the interface was
  provided somewhere) and the phase-loop lane IR then failed closed at execute time
  with missing_producer_dependency — so a reviewed, signed plan could pass its
  canonical validator and design panel, then become non-executable at the
  approval/baseline gate. (O) delegates to the runtime phase_loop_runtime.plan_ir
  (the single source of truth) rather than reimplementing the parse/identity, so
  planning-time and execution-time enforce the same contract by construction — no
  interface-normalization or lane-parser divergence (verified: 0 divergences across all
  22 committed plans). When the runtime is not importable at plan time, (O) skips (the
  execute-time lane IR still enforces the contract). (agent-harness#182)