diff --git a/CHANGELOG.md b/CHANGELOG.md
index d913833..66db849 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,24 +7,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [1.4.0] - 2026-04-28
 
-### Added
+### Memory Quality Cleanup
 
-- Unified memory quality gate in `src/memory-quality.ts` as the single source of truth for all memory quality rules.
-- CRITICAL MEMORY RULES in compaction prompt with explicit good/bad examples.
-- Auto-supersede migration `2026-04-28-quality-cleanup` that marks low-quality compaction memories as superseded on first load.
+- Unified quality gate for compaction memory candidates and cleanup checks.
+- Rewritten compaction memory prompt to reduce over-production of low-quality memories.
+- Conservative one-time quality cleanup migration (`2026-04-28-quality-cleanup`) that supersedes only high-confidence garbage patterns: progress snapshots, raw errors, commit/CI snapshots, temporary status notes, active file snapshots, code/API signatures, path-heavy entries, and empty entries.
+- Soft heuristic failures (`bad_feedback`, `bad_decision`) are intentionally excluded from automatic migration cleanup to protect durable declarative memories such as branding rules, API facts, release rules, and architecture decisions.
+- Migration audit log: `~/.local/share/opencode-working-memory/migration-logs/2026-04-28-quality-cleanup.jsonl`.
+- Extraction rejection log: `~/.local/share/opencode-working-memory/extraction-rejections.jsonl`.
 
-### Changed
+### Recovery note
 
-- Memory quality rules now apply to all memory types, not just project entries.
-- Compaction prompt explicitly instructs model that most compactions should produce zero memories.
-- Low-quality compaction memories (progress snapshots, implementation notes, session-internal notes) are automatically superseded during workspace memory normalization.
-
-### Migration Notes
-
-- Existing low-quality `source: "compaction"` entries will be marked as `superseded` once on first load after upgrade.
-- Explicit and manual memories are never affected by quality cleanup.
-- Superseded entries are retained on disk with `quality_cleanup` tags for audit purposes.
-- Migration is idempotent and runs exactly once per workspace.
+The cleanup migration changes matching entries to `status: "superseded"`; it does not delete the entry. If a useful memory is superseded, inspect the migration audit log and restore by changing that entry back to `status: "active"` in the workspace's `workspace-memory.json`. The migration runs once per workspace.
 
 ## [1.3.3] - 2026-04-28
 
diff --git a/README.md b/README.md
index 9614372..2760930 100644
--- a/README.md
+++ b/README.md
@@ -174,6 +174,8 @@ It includes guards for:
 
 The goal is to remember durable facts, not every detail.
 
+Historical cleanup is intentionally conservative: extraction-time filtering may reject more aggressively, but one-time migration cleanup only supersedes high-confidence garbage patterns. This protects existing durable memories written in declarative style, such as "API endpoint is X" or "Product branding is Y".
+
 ## Configuration
 
 OpenCode Working Memory works out of the box.
diff --git a/scripts/dev/dry-run-migration.ts b/scripts/dev/dry-run-migration.ts
new file mode 100644
index 0000000..807411d
--- /dev/null
+++ b/scripts/dev/dry-run-migration.ts
@@ -0,0 +1,17 @@
+import { loadWorkspaceMemory } from "../../src/workspace-memory.ts";
+
+const roots = [
+  "/Users/sd_wo/work/opencode-working-memory",
+  "/Users/sd_wo/Documents/projects/Pre-cancer-atlas",
+  "/Users/sd_wo/work/opencode-record",
+  "/Users/sd_wo/work/pathology-agent-reports",
+  "/Users/sd_wo/work/pathology-extraction",
+];
+
+for (const root of roots) {
+  console.log(`Loading workspace memory: ${root}`);
+  const store = await loadWorkspaceMemory(root);
+  const active = store.entries.filter(entry => entry.status !== "superseded").length;
+  const superseded = store.entries.filter(entry => entry.status === "superseded").length;
+  console.log(`  active=${active} superseded=${superseded} migrations=${(store.migrations ?? []).join(",")}`);
+}