fix: preserve consumer direction in change completeness

[ilkkasorsa]

STATUS: READY_FOR_REVIEW

task_id: ANATIDACI-R9K4V2MC
task_signature: 🧯🧭🔁
baseline: c34de16a109cafd92abad9eee03b0e891b734dbf
exact head: fd03eaae5db501936591a0a8e7ec5fd585e13f74
Requested Codex model/effort: GPT-6; effort not surfaced in this execution context.

• Accidental upstream PR feat: add change completeness verification plan Graphify-Labs/graphify#3757: closed, not merged.
• Adds the Change Completeness CLI as a six-dimension source-verification plan.
• Reuses shared Missing Impact analysis; Missing Impact candidate budget remains 12.
• Consumer direction follows projected source → target edges. Candidate consumers point to represented changed seeds; changed consumer evidence requires two distinct changed files connected by a consumer relation.
• Jev remains optional semantic reranking only, with at most one request; JEV_INFERRED provenance is retained. No COMPLETE/INCOMPLETE verdict is produced; affected semantics are unchanged.
• Focused verification: uv run --frozen pytest tests/test_change_completeness.py tests/test_missing_impact.py tests/test_affected_cli.py tests/test_jev_shadow.py -q --tb=short — 69 passed.
• git diff --check — passed.
• graphify update . — exited 1; refused to overwrite graphify-out/graph.json because the rebuilt graph had 16,763 nodes while the saved graph had 17,566. Community label refresh was not run.
• Real TypeSafe calls = 0.

No merge performed.