diff --git a/apps/loopover-ui/src/lib/ams-env-reference.ts b/apps/loopover-ui/src/lib/ams-env-reference.ts
index 97c6441a7d..19bcfa5344 100644
--- a/apps/loopover-ui/src/lib/ams-env-reference.ts
+++ b/apps/loopover-ui/src/lib/ams-env-reference.ts
@@ -59,7 +59,7 @@ export const AMS_ENV_REFERENCE_ROWS: MinerEnvReferenceRow[] = [
   {
     name: "LOOPOVER_MINER_GOVERNOR_LEDGER_DB",
     firstReference: "lib/governor-ledger.js",
-    defaultValue: "",
+    defaultValue: null,
   },
   {
     name: "LOOPOVER_MINER_GOVERNOR_STATE_DB",
@@ -84,7 +84,7 @@ export const AMS_ENV_REFERENCE_ROWS: MinerEnvReferenceRow[] = [
   {
     name: "LOOPOVER_MINER_PLAN_STORE_DB",
     firstReference: "lib/plan-store.js",
-    defaultValue: "",
+    defaultValue: null,
   },
   {
     name: "LOOPOVER_MINER_POLICY_DOC_CACHE_DB",
@@ -104,7 +104,7 @@ export const AMS_ENV_REFERENCE_ROWS: MinerEnvReferenceRow[] = [
   {
     name: "LOOPOVER_MINER_PREDICTION_LEDGER_DB",
     firstReference: "lib/prediction-ledger.js",
-    defaultValue: "",
+    defaultValue: null,
   },
   {
     name: "LOOPOVER_MINER_RANKED_CANDIDATES_DB",
@@ -175,16 +175,16 @@ export const AMS_ENV_REFERENCE_MARKDOWN = [
   "| `LOOPOVER_MINER_CONTRIBUTION_PROFILE_CACHE_DB` | `lib/contribution-profile-cache.js` | (none) |",
   '| `LOOPOVER_MINER_DENY_HOOK_SYNTHESIS_DB` | `lib/deny-hook-synthesis.js` | `""` |',
   "| `LOOPOVER_MINER_EVENT_LEDGER_DB` | `lib/event-ledger.js` | (none) |",
-  '| `LOOPOVER_MINER_GOVERNOR_LEDGER_DB` | `lib/governor-ledger.js` | `""` |',
+  "| `LOOPOVER_MINER_GOVERNOR_LEDGER_DB` | `lib/governor-ledger.js` | (none) |",
   "| `LOOPOVER_MINER_GOVERNOR_STATE_DB` | `lib/governor-state.js` | (none) |",
   '| `LOOPOVER_MINER_LOG_LEVEL` | `lib/logger.js` | `""` |',
   '| `LOOPOVER_MINER_NO_UPDATE_CHECK` | `lib/update-check.js` | `""` |',
   '| `LOOPOVER_MINER_ORB_EXPORT_DB` | `lib/orb-export.js` | `""` |',
-  '| `LOOPOVER_MINER_PLAN_STORE_DB` | `lib/plan-store.js` | `""` |',
+  "| `LOOPOVER_MINER_PLAN_STORE_DB` | `lib/plan-store.js` | (none) |",
   "| `LOOPOVER_MINER_POLICY_DOC_CACHE_DB` | `lib/policy-doc-cache.js` | (none) |",
   "| `LOOPOVER_MINER_POLICY_VERDICT_CACHE_DB` | `lib/policy-verdict-cache.js` | (none) |",
   "| `LOOPOVER_MINER_PORTFOLIO_QUEUE_DB` | `lib/portfolio-queue.js` | (none) |",
-  '| `LOOPOVER_MINER_PREDICTION_LEDGER_DB` | `lib/prediction-ledger.js` | `""` |',
+  "| `LOOPOVER_MINER_PREDICTION_LEDGER_DB` | `lib/prediction-ledger.js` | (none) |",
   "| `LOOPOVER_MINER_RANKED_CANDIDATES_DB` | `lib/ranked-candidates.js` | (none) |",
   "| `LOOPOVER_MINER_REPLAY_SNAPSHOT_DB` | `lib/replay-snapshot.js` | (none) |",
   '| `LOOPOVER_MINER_REPO_CLONE_DIR` | `lib/repo-clone.js` | `""` |',
diff --git a/packages/loopover-miner/docs/env-reference.md b/packages/loopover-miner/docs/env-reference.md
index 756223797c..d4429998e1 100644
--- a/packages/loopover-miner/docs/env-reference.md
+++ b/packages/loopover-miner/docs/env-reference.md
@@ -14,16 +14,16 @@ Generated by `npm run miner:env-reference`. Do not edit manually.
 | `LOOPOVER_MINER_CONTRIBUTION_PROFILE_CACHE_DB` | `lib/contribution-profile-cache.js` | (none) |
 | `LOOPOVER_MINER_DENY_HOOK_SYNTHESIS_DB` | `lib/deny-hook-synthesis.js` | `""` |
 | `LOOPOVER_MINER_EVENT_LEDGER_DB` | `lib/event-ledger.js` | (none) |
-| `LOOPOVER_MINER_GOVERNOR_LEDGER_DB` | `lib/governor-ledger.js` | `""` |
+| `LOOPOVER_MINER_GOVERNOR_LEDGER_DB` | `lib/governor-ledger.js` | (none) |
 | `LOOPOVER_MINER_GOVERNOR_STATE_DB` | `lib/governor-state.js` | (none) |
 | `LOOPOVER_MINER_LOG_LEVEL` | `lib/logger.js` | `""` |
 | `LOOPOVER_MINER_NO_UPDATE_CHECK` | `lib/update-check.js` | `""` |
 | `LOOPOVER_MINER_ORB_EXPORT_DB` | `lib/orb-export.js` | `""` |
-| `LOOPOVER_MINER_PLAN_STORE_DB` | `lib/plan-store.js` | `""` |
+| `LOOPOVER_MINER_PLAN_STORE_DB` | `lib/plan-store.js` | (none) |
 | `LOOPOVER_MINER_POLICY_DOC_CACHE_DB` | `lib/policy-doc-cache.js` | (none) |
 | `LOOPOVER_MINER_POLICY_VERDICT_CACHE_DB` | `lib/policy-verdict-cache.js` | (none) |
 | `LOOPOVER_MINER_PORTFOLIO_QUEUE_DB` | `lib/portfolio-queue.js` | (none) |
-| `LOOPOVER_MINER_PREDICTION_LEDGER_DB` | `lib/prediction-ledger.js` | `""` |
+| `LOOPOVER_MINER_PREDICTION_LEDGER_DB` | `lib/prediction-ledger.js` | (none) |
 | `LOOPOVER_MINER_RANKED_CANDIDATES_DB` | `lib/ranked-candidates.js` | (none) |
 | `LOOPOVER_MINER_REPLAY_SNAPSHOT_DB` | `lib/replay-snapshot.js` | (none) |
 | `LOOPOVER_MINER_REPO_CLONE_DIR` | `lib/repo-clone.js` | `""` |
diff --git a/packages/loopover-miner/lib/governor-ledger.js b/packages/loopover-miner/lib/governor-ledger.js
index fd7570b2a3..25528ebbcf 100644
--- a/packages/loopover-miner/lib/governor-ledger.js
+++ b/packages/loopover-miner/lib/governor-ledger.js
@@ -1,7 +1,5 @@
-import { homedir } from "node:os";
-import { join } from "node:path";
 import { normalizeGovernorLedgerEvent } from "@loopover/engine";
-import { openLocalStoreDb } from "./local-store.js";
+import { normalizeLocalStoreDbPath, openLocalStoreDb, resolveLocalStoreDbPath } from "./local-store.js";
 import { applySchemaMigrations } from "./schema-version.js";
 import {
   GOVERNOR_LEDGER_PURGE_SPEC,
@@ -22,26 +20,11 @@ const defaultDbFileName = "governor-ledger.sqlite3";
 let defaultGovernorLedger = null;
 
 export function resolveGovernorLedgerDbPath(env = process.env) {
-  const explicitPath = typeof env.LOOPOVER_MINER_GOVERNOR_LEDGER_DB === "string"
-    ? env.LOOPOVER_MINER_GOVERNOR_LEDGER_DB.trim()
-    : "";
-  if (explicitPath) return explicitPath;
-
-  const explicitConfigDir = typeof env.LOOPOVER_MINER_CONFIG_DIR === "string"
-    ? env.LOOPOVER_MINER_CONFIG_DIR.trim()
-    : "";
-  if (explicitConfigDir) return join(explicitConfigDir, defaultDbFileName);
-
-  const configHome = typeof env.XDG_CONFIG_HOME === "string" && env.XDG_CONFIG_HOME.trim()
-    ? env.XDG_CONFIG_HOME.trim()
-    : join(homedir(), ".config");
-  return join(configHome, "loopover-miner", defaultDbFileName);
+  return resolveLocalStoreDbPath(defaultDbFileName, "LOOPOVER_MINER_GOVERNOR_LEDGER_DB", env);
 }
 
 function normalizeDbPath(dbPath) {
-  const path = (dbPath ?? resolveGovernorLedgerDbPath()).trim();
-  if (!path) throw new Error("invalid_governor_ledger_db_path");
-  return path;
+  return normalizeLocalStoreDbPath(dbPath, resolveGovernorLedgerDbPath(), "invalid_governor_ledger_db_path");
 }
 
 function normalizeOptionalRepoFullName(repoFullName) {
diff --git a/packages/loopover-miner/lib/plan-store.js b/packages/loopover-miner/lib/plan-store.js
index a289648d05..01274d8844 100644
--- a/packages/loopover-miner/lib/plan-store.js
+++ b/packages/loopover-miner/lib/plan-store.js
@@ -1,6 +1,4 @@
-import { homedir } from "node:os";
-import { join } from "node:path";
-import { openLocalStoreDb } from "./local-store.js";
+import { normalizeLocalStoreDbPath, openLocalStoreDb, resolveLocalStoreDbPath } from "./local-store.js";
 import { applySchemaMigrations } from "./schema-version.js";
 
 // Local SQLite persistence for the stateless MCP plan DAG (#2318). `loopover_build_plan`/`plan_status`/
@@ -20,26 +18,11 @@ const defaultDbFileName = "plan-store.sqlite3";
 let defaultPlanStore = null;
 
 export function resolvePlanStoreDbPath(env = process.env) {
-  const explicitPath = typeof env.LOOPOVER_MINER_PLAN_STORE_DB === "string"
-    ? env.LOOPOVER_MINER_PLAN_STORE_DB.trim()
-    : "";
-  if (explicitPath) return explicitPath;
-
-  const explicitConfigDir = typeof env.LOOPOVER_MINER_CONFIG_DIR === "string"
-    ? env.LOOPOVER_MINER_CONFIG_DIR.trim()
-    : "";
-  if (explicitConfigDir) return join(explicitConfigDir, defaultDbFileName);
-
-  const configHome = typeof env.XDG_CONFIG_HOME === "string" && env.XDG_CONFIG_HOME.trim()
-    ? env.XDG_CONFIG_HOME.trim()
-    : join(homedir(), ".config");
-  return join(configHome, "loopover-miner", defaultDbFileName);
+  return resolveLocalStoreDbPath(defaultDbFileName, "LOOPOVER_MINER_PLAN_STORE_DB", env);
 }
 
 function normalizeDbPath(dbPath) {
-  const raw = dbPath ?? resolvePlanStoreDbPath();
-  if (typeof raw !== "string" || !raw.trim()) throw new Error("invalid_plan_store_db_path");
-  return raw.trim();
+  return normalizeLocalStoreDbPath(dbPath, resolvePlanStoreDbPath(), "invalid_plan_store_db_path");
 }
 
 function normalizePlanId(planId) {
diff --git a/packages/loopover-miner/lib/prediction-ledger.js b/packages/loopover-miner/lib/prediction-ledger.js
index b27b63f09f..cdba896920 100644
--- a/packages/loopover-miner/lib/prediction-ledger.js
+++ b/packages/loopover-miner/lib/prediction-ledger.js
@@ -1,6 +1,4 @@
-import { homedir } from "node:os";
-import { join } from "node:path";
-import { openLocalStoreDb } from "./local-store.js";
+import { normalizeLocalStoreDbPath, openLocalStoreDb, resolveLocalStoreDbPath } from "./local-store.js";
 import { applySchemaMigrations } from "./schema-version.js";
 import {
   PREDICTION_LEDGER_PURGE_SPEC,
@@ -24,26 +22,11 @@ const defaultDbFileName = "prediction-ledger.sqlite3";
 let defaultPredictionLedger = null;
 
 export function resolvePredictionLedgerDbPath(env = process.env) {
-  const explicitPath = typeof env.LOOPOVER_MINER_PREDICTION_LEDGER_DB === "string"
-    ? env.LOOPOVER_MINER_PREDICTION_LEDGER_DB.trim()
-    : "";
-  if (explicitPath) return explicitPath;
-
-  const explicitConfigDir = typeof env.LOOPOVER_MINER_CONFIG_DIR === "string"
-    ? env.LOOPOVER_MINER_CONFIG_DIR.trim()
-    : "";
-  if (explicitConfigDir) return join(explicitConfigDir, defaultDbFileName);
-
-  const configHome = typeof env.XDG_CONFIG_HOME === "string" && env.XDG_CONFIG_HOME.trim()
-    ? env.XDG_CONFIG_HOME.trim()
-    : join(homedir(), ".config");
-  return join(configHome, "loopover-miner", defaultDbFileName);
+  return resolveLocalStoreDbPath(defaultDbFileName, "LOOPOVER_MINER_PREDICTION_LEDGER_DB", env);
 }
 
 function normalizeDbPath(dbPath) {
-  const path = (dbPath ?? resolvePredictionLedgerDbPath()).trim();
-  if (!path) throw new Error("invalid_prediction_ledger_db_path");
-  return path;
+  return normalizeLocalStoreDbPath(dbPath, resolvePredictionLedgerDbPath(), "invalid_prediction_ledger_db_path");
 }
 
 function normalizeRepoFullName(repoFullName) {