chore(p0): drop never-enabled hunter tools, test-only functions and receiver delivery

Off every active line (PATHFINDER-2026-10-13/03-unified-proposal.md, cuts).
Deleted: the four hunter tools no caller enables (read_definition,
entry_points, flows, obligations) with their schemas and dispatch, the dead
mapping branch of find_refs; 20 functions whose only caller was one test
(mapping task records, compute_ranking_metrics, build_quick_hunter_prompt,
validate_evidence_transition, should_fuse, harness processors,
rank_targets_with_model, model/report slice rendering, taxonomy
hierarchical/related, config_value.verdict, taint.verdict, roles.load_roles,
features.language_of and build_for_scan, folds.leave_one_*,
features.recorded_case, search BatchExecutor and the three __main__ shims,
delivery.put_input); the receiver delivery mode of the plane. push_inputs.py
moved to benchmarks/push. memory.purge stays: the live-S3 test cleanup uses
it. Net: 2,730 lines deleted, 207 added. 473 targeted tests passed; 3,282
tests collect. breadth.toml records the removals.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

tests/test_fusion.py

@@ -6,13 +6,7 @@ from pathlib import Path
 import pytest
 
 from openultrasast.findings import StaticFinding
-from openultrasast.fusion import (
-    FusionDisposition,
-    fuse_finding,
-    fuse_findings,
-    fusion_triggers,
-    should_fuse,
-)
+from openultrasast.fusion import FusionDisposition, fuse_finding, fuse_findings, fusion_triggers
 from openultrasast.verification import EvidenceLevel, VerificationResult, VerificationStatus
 
 
@@ -63,10 +57,6 @@ def test_triggers_on_high_severity_and_reachable() -> None:
     assert "gates_risky_fix" in triggers
 
 
-def test_low_severity_unreachable_does_not_trigger() -> None:
-    assert not should_fuse(_finding(severity="low", reachability="unknown"))
-
-
 def test_verifier_disagreement_triggers() -> None:
     triggers = fusion_triggers(
         _finding(severity="low", reachability="unknown"),
@@ -83,10 +73,6 @@ def test_evidence_conflict_triggers_when_rejected_but_reachable() -> None:
     assert "evidence_conflict" in triggers
 
 
-def test_high_assurance_request_forces_a_trigger() -> None:
-    assert should_fuse(_finding(severity="low", reachability="unknown"), high_assurance=True)
-
-
 # ---- deterministic two-panel decider + dispositions -------------------------