diff --git a/src/resources/extensions/sf/sf-db/sf-db-core.js b/src/resources/extensions/sf/sf-db/sf-db-core.js
index 06fdda29d..d8606f98e 100644
--- a/src/resources/extensions/sf/sf-db/sf-db-core.js
+++ b/src/resources/extensions/sf/sf-db/sf-db-core.js
@@ -294,11 +294,28 @@ export function isEmptyMilestoneSpec(row) {
 		(row["product_research_json"] ?? "") === ""
 	);
 }
-let currentDb = null;
-let currentPath = null;
-let currentPid = 0;
-let _exitHandlerRegistered = false;
-let _dbOpenAttempted = false;
+// Process-wide singleton state for the open project DB connection.
+//
+// Stored on globalThis under a well-known Symbol so multiple module
+// instances loaded into the same Node process — e.g. one via normal ESM
+// resolution from the autonomous loop and one via `jiti.import()` from
+// `src/headless-feedback.ts` — share the same connection slot. Without
+// this shared backing each module instance opened its own SQLite handle to
+// the same `.sf/sf.db`, producing intra-process write contention (the
+// SQLITE_BUSY / writer-stall pattern that hung the in-process drainer for
+// `sf headless feedback ...` while the autonomous loop ran). See
+// sf-mpa4g46x-jixg3x for the original report and codex's diagnosis.
+//
+// All five fields formerly stored as module-level `let` are now read/written
+// through `_sf.<field>` so every module instance points at the same slot.
+const _SF_DB_GLOBAL = Symbol.for("singularity-forge:sf-db:state");
+const _sf = (globalThis[_SF_DB_GLOBAL] ??= {
+	currentDb: null,
+	currentPath: null,
+	currentPid: 0,
+	_exitHandlerRegistered: false,
+	_dbOpenAttempted: false,
+});
 /**
  * Get the name of the SQLite provider currently loaded (or null if unavailable).
  */
@@ -310,7 +327,7 @@ export function getDbProvider() {
  * Check if the database is currently open and available for queries.
  */
 export function isDbAvailable() {
-	return currentDb !== null;
+	return _sf.currentDb !== null;
 }
 /**
  * Returns true if openDatabase() has been called at least once this session.
@@ -319,21 +336,21 @@ export function isDbAvailable() {
  * trigger a false degraded-mode warning.
  */
 export function wasDbOpenAttempted() {
-	return _dbOpenAttempted;
+	return _sf._dbOpenAttempted;
 }
 /**
  * Get the current database adapter, or null if the database is not open.
  */
 export function getDatabase() {
-	return currentDb;
+	return _sf.currentDb;
 }
 /**
  * Open the database at the specified path. Returns true if successful.
  */
 export function openDatabase(path) {
-	_dbOpenAttempted = true;
-	if (currentDb && currentPath !== path) closeDatabase();
-	if (currentDb && currentPath === path) return true;
+	_sf._dbOpenAttempted = true;
+	if (_sf.currentDb && _sf.currentPath !== path) closeDatabase();
+	if (_sf.currentDb && _sf.currentPath === path) return true;
 	const rawDb = openRawDb(path);
 	if (!rawDb) return false;
 	const adapter = createAdapter(rawDb);
@@ -374,11 +391,11 @@ export function openDatabase(path) {
 			throw err;
 		}
 	}
-	currentDb = adapter;
-	currentPath = path;
-	currentPid = process.pid;
-	if (!_exitHandlerRegistered) {
-		_exitHandlerRegistered = true;
+	_sf.currentDb = adapter;
+	_sf.currentPath = path;
+	_sf.currentPid = process.pid;
+	if (!_sf._exitHandlerRegistered) {
+		_sf._exitHandlerRegistered = true;
 		process.on("exit", () => {
 			try {
 				closeDatabase();
@@ -404,9 +421,9 @@ export function openDatabase(path) {
  * Consumer: runFinalize() in auto/phases.js after each successful unit.
  */
 export function checkpointWal() {
-	if (!currentDb) return;
+	if (!_sf.currentDb) return;
 	try {
-		currentDb.exec("PRAGMA wal_checkpoint(PASSIVE)");
+		_sf.currentDb.exec("PRAGMA wal_checkpoint(PASSIVE)");
 	} catch (e) {
 		logWarning("db", `WAL checkpoint failed: ${getErrorMessage(e)}`);
 	}
@@ -416,27 +433,27 @@ export function checkpointWal() {
  * Close the database connection.
  */
 export function closeDatabase() {
-	if (currentDb) {
+	if (_sf.currentDb) {
 		try {
-			currentDb.exec("PRAGMA wal_checkpoint(TRUNCATE)");
+			_sf.currentDb.exec("PRAGMA wal_checkpoint(TRUNCATE)");
 		} catch (e) {
 			logWarning("db", `WAL checkpoint failed: ${e.message}`);
 		}
 		try {
 			// Incremental vacuum to reclaim space without blocking
-			currentDb.exec("PRAGMA incremental_vacuum(64)");
+			_sf.currentDb.exec("PRAGMA incremental_vacuum(64)");
 		} catch (e) {
 			logWarning("db", `incremental vacuum failed: ${e.message}`);
 		}
 		try {
-			currentDb.close();
+			_sf.currentDb.close();
 		} catch (e) {
 			logWarning("db", `database close failed: ${e.message}`);
 		}
-		currentDb = null;
-		currentPath = null;
-		currentPid = 0;
-		_dbOpenAttempted = false;
+		_sf.currentDb = null;
+		_sf.currentPath = null;
+		_sf.currentPid = 0;
+		_sf._dbOpenAttempted = false;
 	}
 }
 /** Run a full VACUUM — call sparingly (e.g. after milestone completion). */
@@ -444,9 +461,9 @@ export function closeDatabase() {
  * Vacuum the database to reclaim disk space and optimize.
  */
 export function vacuumDatabase() {
-	if (!currentDb) return;
+	if (!_sf.currentDb) return;
 	try {
-		currentDb.exec("VACUUM");
+		_sf.currentDb.exec("VACUUM");
 	} catch (e) {
 		logWarning("db", `VACUUM failed: ${e.message}`);
 	}
@@ -456,7 +473,7 @@ let _txDepth = 0;
  * Execute a callback within a database transaction (BEGIN...COMMIT or ROLLBACK).
  */
 export function transaction(fn) {
-	if (!currentDb) throw new SFError(SF_STALE_STATE, "sf-db: No database open");
+	if (!_sf.currentDb) throw new SFError(SF_STALE_STATE, "sf-db: No database open");
 	// Re-entrant: if already inside a transaction, just run fn() without
 	// starting a new one. SQLite does not support nested BEGIN/COMMIT.
 	if (_txDepth > 0) {
@@ -468,13 +485,13 @@ export function transaction(fn) {
 		}
 	}
 	_txDepth++;
-	currentDb.exec("BEGIN");
+	_sf.currentDb.exec("BEGIN");
 	try {
 		const result = fn();
-		currentDb.exec("COMMIT");
+		_sf.currentDb.exec("COMMIT");
 		return result;
 	} catch (err) {
-		currentDb.exec("ROLLBACK");
+		_sf.currentDb.exec("ROLLBACK");
 		throw err;
 	} finally {
 		_txDepth--;
@@ -491,7 +508,7 @@ export function transaction(fn) {
  * Execute a callback within a read-only database transaction.
  */
 export function readTransaction(fn) {
-	if (!currentDb) throw new SFError(SF_STALE_STATE, "sf-db: No database open");
+	if (!_sf.currentDb) throw new SFError(SF_STALE_STATE, "sf-db: No database open");
 	if (_txDepth > 0) {
 		_txDepth++;
 		try {
@@ -501,14 +518,14 @@ export function readTransaction(fn) {
 		}
 	}
 	_txDepth++;
-	currentDb.exec("BEGIN DEFERRED");
+	_sf.currentDb.exec("BEGIN DEFERRED");
 	try {
 		const result = fn();
-		currentDb.exec("COMMIT");
+		_sf.currentDb.exec("COMMIT");
 		return result;
 	} catch (err) {
 		try {
-			currentDb.exec("ROLLBACK");
+			_sf.currentDb.exec("ROLLBACK");
 		} catch (rollbackErr) {
 			// A failed ROLLBACK after a failed read is a split-brain signal —
 			// the transaction is in an indeterminate state. Surface it via the
@@ -523,14 +540,14 @@ export function readTransaction(fn) {
 	}
 }
 export function getDbOwnerPid() {
-	return currentPid;
+	return _sf.currentPid;
 }
 export function getDbPath() {
-	return currentPath;
+	return _sf.currentPath;
 }
 
 export function _getAdapter() {
-	return currentDb;
+	return _sf.currentDb;
 }
 export function _resetProvider() {
 	loadAttempted = false;
@@ -538,7 +555,7 @@ export function _resetProvider() {
 
 export function insertMilestoneSpecIfAbsent(milestoneId, planning = {}) {
 	if (!hasPlanningPayload(planning)) return;
-	const existing = currentDb
+	const existing = _sf.currentDb
 		.prepare("SELECT * FROM milestone_specs WHERE id = ?")
 		.get(milestoneId);
 	if (existing && !isEmptyMilestoneSpec(existing)) return;
@@ -565,7 +582,7 @@ export function insertMilestoneSpecIfAbsent(milestoneId, planning = {}) {
 	};
 	if (existing) {
 		const { ":created_at": _createdAt, ...updateParams } = params;
-		currentDb
+		_sf.currentDb
 			.prepare(`UPDATE milestone_specs SET
 	      vision = :vision,
 	      success_criteria = :success_criteria,
@@ -584,7 +601,7 @@ export function insertMilestoneSpecIfAbsent(milestoneId, planning = {}) {
 			.run(updateParams);
 		return;
 	}
-	currentDb
+	_sf.currentDb
 		.prepare(`INSERT OR IGNORE INTO milestone_specs (
       id, vision, success_criteria, key_risks, proof_strategy,
       verification_contract, verification_integration, verification_operational, verification_uat,
@@ -600,7 +617,7 @@ export function insertMilestoneSpecIfAbsent(milestoneId, planning = {}) {
 }
 
 export function insertSliceSpecIfAbsent(milestoneId, sliceId, planning = {}) {
-	currentDb
+	_sf.currentDb
 		.prepare(`INSERT OR IGNORE INTO slice_specs (
       milestone_id, slice_id, goal, success_criteria, proof_level,
       integration_closure, observability_impact,
@@ -681,7 +698,7 @@ export function insertTaskSpecIfAbsent(
 			"sf-db:insertTaskSpec",
 			`frontmatter validation errors for ${milestoneId}/${sliceId}/${taskId}: ${errors.join(", ")}`,
 		);
-	currentDb
+	_sf.currentDb
 		.prepare(`INSERT OR IGNORE INTO task_specs (
       milestone_id, slice_id, task_id, verify, inputs, expected_output,
       risk, mutation_scope, verification_type, plan_approval, estimated_effort,
@@ -715,9 +732,9 @@ export function insertTaskSpecIfAbsent(
 }
 
 export function insertTaskSchedulerIfAbsent(milestoneId, sliceId, taskId) {
-	const currentDb = _getAdapter();
-	if (!currentDb) throw new SFError(SF_STALE_STATE, "sf-db: No database open");
-	currentDb
+	const localDb = _getAdapter();
+	if (!localDb) throw new SFError(SF_STALE_STATE, "sf-db: No database open");
+	localDb
 		.prepare(`INSERT OR IGNORE INTO task_scheduler (
         milestone_id, slice_id, task_id, status, updated_at
       ) VALUES (
@@ -1034,7 +1051,7 @@ export function rowToGate(row) {
 export function capErrorForStorage(error, runId) {
 	if (!error || error.length <= MAX_ERROR_STORED_BYTES) return error;
 	try {
-		const errDir = join(dirname(currentPath), "runtime", "errors");
+		const errDir = join(dirname(_sf.currentPath), "runtime", "errors");
 		mkdirSync(errDir, { recursive: true });
 		writeFileSync(join(errDir, `${runId}.txt`), error, "utf-8");
 	} catch {