C.E.L_Slide_test2/.orchestrator/tmp/imp12_u1_comment.md

Executing unit: u1

[Claude #3] Stage 3 code-edit Round #1 — unit u1

unit_executed

• id: u1
• summary: Extend plan_zone_ratio_retry from single-primary-donor to multi-donor greedy aggregation; add donors_used + aggregate_slack_used to plan dict.

files_changed

• src/phase_z2_retry.py (33 insertions, 13 deletions; net +20 lines, within u1 estimate ≤35)

diff_summary

Replaced single-donor feasibility branch in plan_zone_ratio_retry with multi-donor greedy aggregation along slack-desc donor order (already sorted):

1. Feasibility check — compare target_added_px against aggregate_slack_available = sum(d.slack for d in donor_candidates) instead of primary_donor.slack.
2. Greedy allocation — when feasible, walk donor_candidates in slack-desc order, taking min(donor.slack, remaining) from each until remaining == 0. Each donor contributes only what is needed; later donors with sufficient remaining slack are untouched.
3. New plan fields — donors_used: list[dict] with {position, reduced_px, slack_before, slack_after} per donor; aggregate_slack_used: int; aggregate_slack_available: int.
4. Backward-compat surface preserved — donor_zone_position (primary donor), donor_reduced_px (primary donor's take, not total), donor_max_slack (primary donor's slack on failure path). Pipeline log line at phase_z2_pipeline.py:1886 continues to render without change (u9 will update for multi-donor telemetry).
5. Failure-reason classifier preservation — failure_reason text retains primary donor ... slack ... target_added_px substrings (feedback_phase_z2_failure_router.py:126-130 matches), so existing donor_slack_insufficient classification still fires on aggregate-insufficient case. u2/u3 will rewire routing.

evidence

• python -c "from src.phase_z2_retry import plan_zone_ratio_retry; print('OK')" → OK
• python -m pytest -q tests/phase_z2 → 62 passed in 0.13s (regression-free; u10 will add the multi-donor unit tests)
• git diff --stat src/phase_z2_retry.py → 1 file changed, 33 insertions(+), 13 deletions(-)
• Scope: 1 file modified (matches u1 files: [src/phase_z2_retry.py]); no other source file touched.

scope_lock_compliance

• ✅ deterministic (no AI call added) — feedback_ai_isolation_contract
• ✅ no global spacing shrink (planner only manipulates donor zone heights within min_height_px floor) — feedback_phase_z_spacing_direction
• ✅ no ACTION_BY_CATEGORY change — Stage 1 scope_lock
• ✅ files ≤3 and estimate_lines ≤50 — actual: 1 file, +33/-13
• ✅ retry_budget=1 preserved (no orchestrator change in this unit)
• ✅ failure_reason substring stability preserves u2/u3 classifier surface

remaining_units

• u2 — failure_router classifier extension (3 new salvage failure types)
• u3 — NEXT_ACTION_BY_FAILURE rewire (donor_slack_insufficient → cross_zone_redistribute)
• u4 — plan_cross_zone_redistribute + scoped role-height CSS
• u5 — plan_glue_compression + frame-scoped CSS
• u6 — plan_font_step_compression + zone-scoped CSS
• u7 — ACTION_IMPLEMENTATION_STATUS registration for 3 new salvage actions
• u8 — _attempt_salvage_chain orchestrator (Step 17 pipeline)
• u9 — pipeline wiring + Step 17 telemetry (salvage_steps, salvage_passed)
• u10 — multi-donor plan tests
• u11 — plan_cross_zone_redistribute tests
• u12 — plan_glue_compression tests
• u13 — plan_font_step_compression tests
• u14 — failure_router cascade tests
• u15 — end-to-end _attempt_salvage_chain tests

follow_up_issue_candidates

None. All observed deviations are addressed by remaining units (u9 will update the pipeline log line; u2 will replace substring-matching classifier with explicit feasibility-branch signal).

next

u2 — extend phase_z2_failure_router classifier to surface 3 new salvage failure types (cross_zone_redistribute_insufficient, glue_absorption_insufficient, font_step_insufficient).

rewind_target: continue_same FINAL_CONSENSUS: NO