diff --git a/__tests__/arkts-resolution.test.ts b/__tests__/arkts-resolution.test.ts
index b095a4433..53825498a 100644
--- a/__tests__/arkts-resolution.test.ts
+++ b/__tests__/arkts-resolution.test.ts
@@ -25,7 +25,12 @@ beforeAll(async () => {
 
 describe('ArkTS attribute-chain resolution precision', () => {
   let tmpDir: string | undefined;
+  let cg: CodeGraph | undefined;
   afterEach(() => {
+    // Windows refuses to remove a directory holding an open file, so the
+    // graph's SQLite handle has to go before the temp project does.
+    cg?.close();
+    cg = undefined;
     if (tmpDir) fs.rmSync(tmpDir, { recursive: true, force: true });
     tmpDir = undefined;
   });
@@ -65,7 +70,7 @@ describe('ArkTS attribute-chain resolution precision', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const fns = cg.getNodesByKind('function');
@@ -99,7 +104,12 @@ describe('ArkTS attribute-chain resolution precision', () => {
 
 describe('ArkTS ohpm workspace import resolution', () => {
   let tmpDir: string | undefined;
+  let cg: CodeGraph | undefined;
   afterEach(() => {
+    // Windows refuses to remove a directory holding an open file, so the
+    // graph's SQLite handle has to go before the temp project does.
+    cg?.close();
+    cg = undefined;
     if (tmpDir) fs.rmSync(tmpDir, { recursive: true, force: true });
     tmpDir = undefined;
   });
@@ -146,7 +156,7 @@ describe('ArkTS ohpm workspace import resolution', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const classes = cg.getNodesByKind('class');
@@ -168,7 +178,12 @@ describe('ArkTS ohpm workspace import resolution', () => {
 
 describe('ArkUI state → build() re-render bridge (assignment-gated)', () => {
   let tmpDir: string | undefined;
+  let cg: CodeGraph | undefined;
   afterEach(() => {
+    // Windows refuses to remove a directory holding an open file, so the
+    // graph's SQLite handle has to go before the temp project does.
+    cg?.close();
+    cg = undefined;
     if (tmpDir) fs.rmSync(tmpDir, { recursive: true, force: true });
     tmpDir = undefined;
   });
@@ -201,7 +216,7 @@ describe('ArkUI state → build() re-render bridge (assignment-gated)', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const methods = cg.getNodesByKind('method');
@@ -229,7 +244,12 @@ describe('ArkUI state → build() re-render bridge (assignment-gated)', () => {
 
 describe('ArkUI @ohos.events.emitter bridge', () => {
   let tmpDir: string | undefined;
+  let cg: CodeGraph | undefined;
   afterEach(() => {
+    // Windows refuses to remove a directory holding an open file, so the
+    // graph's SQLite handle has to go before the temp project does.
+    cg?.close();
+    cg = undefined;
     if (tmpDir) fs.rmSync(tmpDir, { recursive: true, force: true });
     tmpDir = undefined;
   });
@@ -266,7 +286,7 @@ describe('ArkUI @ohos.events.emitter bridge', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const methods = cg.getNodesByKind('method');
@@ -299,7 +319,7 @@ describe('ArkUI @ohos.events.emitter bridge', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const fns = cg.getNodesByKind('function');
@@ -314,7 +334,12 @@ describe('ArkUI @ohos.events.emitter bridge', () => {
 
 describe('ArkUI router bridge (pushUrl literal → @Entry struct)', () => {
   let tmpDir: string | undefined;
+  let cg: CodeGraph | undefined;
   afterEach(() => {
+    // Windows refuses to remove a directory holding an open file, so the
+    // graph's SQLite handle has to go before the temp project does.
+    cg?.close();
+    cg = undefined;
     if (tmpDir) fs.rmSync(tmpDir, { recursive: true, force: true });
     tmpDir = undefined;
   });
@@ -343,7 +368,7 @@ describe('ArkUI router bridge (pushUrl literal → @Entry struct)', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const methods = cg.getNodesByKind('method');
@@ -362,7 +387,12 @@ describe('ArkUI router bridge (pushUrl literal → @Entry struct)', () => {
 
 describe('ohpm main entry (custom barrel + .ts consumer)', () => {
   let tmpDir: string | undefined;
+  let cg: CodeGraph | undefined;
   afterEach(() => {
+    // Windows refuses to remove a directory holding an open file, so the
+    // graph's SQLite handle has to go before the temp project does.
+    cg?.close();
+    cg = undefined;
     if (tmpDir) fs.rmSync(tmpDir, { recursive: true, force: true });
     tmpDir = undefined;
   });
@@ -408,7 +438,7 @@ describe('ohpm main entry (custom barrel + .ts consumer)', () => {
         '}\n'
     );
 
-    const cg = CodeGraph.initSync(tmpDir);
+    cg = CodeGraph.initSync(tmpDir);
     await cg.indexAll();
 
     const classes = cg.getNodesByKind('class');
diff --git a/__tests__/frameworks-integration.test.ts b/__tests__/frameworks-integration.test.ts
index 3df4f2d88..533018fb3 100644
--- a/__tests__/frameworks-integration.test.ts
+++ b/__tests__/frameworks-integration.test.ts
@@ -788,6 +788,8 @@ describe('JVM FQN imports — end-to-end', () => {
 
     const edge = cg.getIncomingEdges(util!.id).find((e) => e.kind === 'imports');
     expect(edge, 'imports edge should reach the top-level function by FQN').toBeDefined();
+
+    cg.close();
   });
 
   it('resolves cross-language: Kotlin importing a Java class', async () => {
@@ -809,6 +811,8 @@ describe('JVM FQN imports — end-to-end', () => {
 
     const edge = cg.getIncomingEdges(javaBar!.id).find((e) => e.kind === 'imports');
     expect(edge, 'Kotlin caller should resolve its import to the Java class').toBeDefined();
+
+    cg.close();
   });
 
   it('disambiguates a class-name collision across packages', async () => {
@@ -854,6 +858,8 @@ describe('JVM FQN imports — end-to-end', () => {
       edges.map((e) => cg.getNode(e.source)?.filePath).filter(Boolean);
     expect(sourceFiles(alphaIncoming).some((p) => p?.includes('CallerA.kt'))).toBe(true);
     expect(sourceFiles(betaIncoming).some((p) => p?.includes('CallerB.kt'))).toBe(true);
+
+    cg.close();
   });
 });
 
diff --git a/__tests__/mcp-daemon.test.ts b/__tests__/mcp-daemon.test.ts
index c73ac564c..fd74c1d14 100644
--- a/__tests__/mcp-daemon.test.ts
+++ b/__tests__/mcp-daemon.test.ts
@@ -193,10 +193,25 @@ describe('Shared MCP daemon (issue #411)', () => {
     const daemonPid = readLockPid(realRoot);
     if (daemonPid && daemonPid !== process.pid && isAlive(daemonPid)) {
       try { process.kill(daemonPid, 'SIGKILL'); } catch { /* race */ }
+      await waitProcessExit(daemonPid, 5000);
     }
-    await new Promise((r) => setTimeout(r, 50));
+    // A signalled process still holds its file handles until it is actually
+    // gone, and Windows refuses to remove a directory holding an open file — so
+    // wait for each exit rather than for a fixed grace period.
+    await Promise.all(
+      servers.map(({ child }) =>
+        child.exitCode === null && child.signalCode === null
+          ? new Promise<void>((r) => child.once('exit', () => r()))
+          : Promise.resolve()
+      )
+    );
     servers.length = 0;
-    fs.rmSync(tempDir, { recursive: true, force: true });
+    // These tests deliberately leave a detached daemon alive, and a losing
+    // launcher can leave a candidate of its own mid-exit; either still holds
+    // the directory for a moment after the pid above is gone. Windows will not
+    // remove a directory holding an open file, so retry for a few seconds
+    // rather than assume the handles are released the instant the pid is.
+    fs.rmSync(tempDir, { recursive: true, force: true, maxRetries: 60, retryDelay: 100 });
   });
 
   it('two invocations share ONE detached daemon; both attach as proxies', async () => {
diff --git a/__tests__/mcp-initialize.test.ts b/__tests__/mcp-initialize.test.ts
index 0a320773d..9f95cecb0 100644
--- a/__tests__/mcp-initialize.test.ts
+++ b/__tests__/mcp-initialize.test.ts
@@ -107,12 +107,23 @@ describe('MCP initialize handshake (issue #172)', () => {
     tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-mcp-init-'));
   });
 
-  afterEach(() => {
-    if (child && !child.killed) {
-      child.kill('SIGKILL');
+  afterEach(async () => {
+    // A signalled child still holds its file handles until it is actually gone,
+    // and Windows refuses to remove a directory holding an open file — so wait
+    // for the exit, rather than only sending the signal.
+    if (child) {
+      const proc = child;
       child = null;
+      if (proc.exitCode === null && proc.signalCode === null) {
+        await new Promise<void>((resolve) => {
+          proc.once('exit', () => resolve());
+          proc.kill('SIGKILL');
+        });
+      }
     }
-    fs.rmSync(tempDir, { recursive: true, force: true });
+    // The server may have started a detached daemon this suite does not track,
+    // so retry the removal while any straggler releases the directory.
+    fs.rmSync(tempDir, { recursive: true, force: true, maxRetries: 20, retryDelay: 50 });
   });
 
   it('responds to initialize quickly when no .codegraph exists in cwd', async () => {
diff --git a/__tests__/mcp-roots.test.ts b/__tests__/mcp-roots.test.ts
index 8e1d4520d..dd9569884 100644
--- a/__tests__/mcp-roots.test.ts
+++ b/__tests__/mcp-roots.test.ts
@@ -84,13 +84,24 @@ describe('MCP project resolution via roots/list (issue #196)', () => {
     projectDir = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-mcp-proj-'));
   });
 
-  afterEach(() => {
-    if (child && !child.killed) {
-      child.kill('SIGKILL');
+  afterEach(async () => {
+    // A signalled child still holds its file handles until it is actually gone,
+    // and Windows refuses to remove a directory holding an open file — so wait
+    // for the exit, rather than only sending the signal.
+    if (child) {
+      const proc = child;
       child = null;
+      if (proc.exitCode === null && proc.signalCode === null) {
+        await new Promise<void>((resolve) => {
+          proc.once('exit', () => resolve());
+          proc.kill('SIGKILL');
+        });
+      }
     }
-    fs.rmSync(cwdDir, { recursive: true, force: true });
-    fs.rmSync(projectDir, { recursive: true, force: true });
+    // The server may have started a detached daemon this suite does not track,
+    // so retry the removal while any straggler releases the directory.
+    fs.rmSync(cwdDir, { recursive: true, force: true, maxRetries: 20, retryDelay: 50 });
+    fs.rmSync(projectDir, { recursive: true, force: true, maxRetries: 20, retryDelay: 50 });
   });
 
   it('resolves the project from the client roots/list when no rootUri is sent', async () => {
diff --git a/__tests__/mcp-subproject-adoption.test.ts b/__tests__/mcp-subproject-adoption.test.ts
index 39abac038..ca0068da3 100644
--- a/__tests__/mcp-subproject-adoption.test.ts
+++ b/__tests__/mcp-subproject-adoption.test.ts
@@ -113,12 +113,23 @@ describe('MCP workspace sub-project adoption (#1606) + no-default diagnostics (#
     ws = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-mcp-ws-'));
   });
 
-  afterEach(() => {
-    if (child && !child.killed) {
-      child.kill('SIGKILL');
+  afterEach(async () => {
+    // A signalled child still holds its file handles until it is actually gone,
+    // and Windows refuses to remove a directory holding an open file — so wait
+    // for the exit, rather than only sending the signal.
+    if (child) {
+      const proc = child;
       child = null;
+      if (proc.exitCode === null && proc.signalCode === null) {
+        await new Promise<void>((resolve) => {
+          proc.once('exit', () => resolve());
+          proc.kill('SIGKILL');
+        });
+      }
     }
-    fs.rmSync(ws, { recursive: true, force: true });
+    // The server may have started a detached daemon this suite does not track,
+    // so retry the removal while any straggler releases the directory.
+    fs.rmSync(ws, { recursive: true, force: true, maxRetries: 20, retryDelay: 50 });
   });
 
   it('adopts the single indexed sub-project below a workspace root as the default project', async () => {
diff --git a/__tests__/resolution.test.ts b/__tests__/resolution.test.ts
index decaadee5..ab8c49eb6 100644
--- a/__tests__/resolution.test.ts
+++ b/__tests__/resolution.test.ts
@@ -3570,6 +3570,7 @@ int run() {
     // feature can't silently regress to a no-op in the indexing flow.
     it('connects #include to the real header file via include-dir scan (end-to-end)', async () => {
       const tempProject = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-cpp-e2e-'));
+      let db: DatabaseConnection | undefined;
       try {
         fs.mkdirSync(path.join(tempProject, 'include'), { recursive: true });
         fs.mkdirSync(path.join(tempProject, 'src'), { recursive: true });
@@ -3592,7 +3593,7 @@ int run() {
         // The `#include "utils.h"` edge should target the real
         // `include/utils.h` file node — not a floating `import` node
         // living inside main.cpp.
-        const db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
+        db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
         const rows = db.getDb().prepare(`
           select dst.kind as dstKind, dst.file_path as dstPath
           from edges e
@@ -3612,6 +3613,10 @@ int run() {
         );
         expect(stdlibFile).toBeUndefined();
       } finally {
+        // Windows refuses to remove a directory holding an open file: both the
+        // graph's handle and this test's own one have to go first.
+        db?.close();
+        cg?.close();
         fs.rmSync(tempProject, { recursive: true, force: true });
       }
     });
@@ -3684,6 +3689,7 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
     });
 
     it('resolves require_once to a file→file imports edge (#660)', async () => {
+      let db: DatabaseConnection | undefined;
       const tempProject = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-php-e2e-'));
       try {
         fs.mkdirSync(path.join(tempProject, 'src'), { recursive: true });
@@ -3701,7 +3707,7 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
         // reporter's repro: page.php's `require_once("lib.php")` must resolve
         // to the real src/lib.php file node — a file→file `imports` edge, so
         // callers(lib.php) now includes page.php.
-        const db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
+        db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
         const rows = db.getDb().prepare(`
           select dst.kind as dstKind, dst.file_path as dstPath
           from edges e
@@ -3716,11 +3722,16 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
         );
         expect(resolved, 'page.php → src/lib.php imports edge missing').toBeDefined();
       } finally {
+        // Windows refuses to remove a directory holding an open file: both the
+        // graph's handle and this test's own one have to go first.
+        db?.close();
+        cg?.close();
         fs.rmSync(tempProject, { recursive: true, force: true });
       }
     });
 
     it('resolves a subdirectory include path to the correct file (#660)', async () => {
+      let db: DatabaseConnection | undefined;
       const tempProject = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-php-subdir-'));
       try {
         fs.mkdirSync(path.join(tempProject, 'inc'), { recursive: true });
@@ -3735,7 +3746,7 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
 
         cg = await CodeGraph.init(tempProject, { index: true });
 
-        const db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
+        db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
         const rows = db.getDb().prepare(`
           select dst.kind as dstKind, dst.file_path as dstPath
           from edges e
@@ -3750,11 +3761,16 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
           'index.php → inc/db.php imports edge missing'
         ).toBeDefined();
       } finally {
+        // Windows refuses to remove a directory holding an open file: both the
+        // graph's handle and this test's own one have to go first.
+        db?.close();
+        cg?.close();
         fs.rmSync(tempProject, { recursive: true, force: true });
       }
     });
 
     it('does not mis-connect an unresolvable include to a same-named file elsewhere (#660)', async () => {
+      let db: DatabaseConnection | undefined;
       const tempProject = fs.mkdtempSync(path.join(os.tmpdir(), 'codegraph-php-misresolve-'));
       try {
         // app/page.php's `require "inc/db.php"` resolves relative to app/, where
@@ -3774,7 +3790,7 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
 
         cg = await CodeGraph.init(tempProject, { index: true });
 
-        const db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
+        db = DatabaseConnection.open(path.join(tempProject, '.codegraph', 'codegraph.db'));
         const rows = db.getDb().prepare(`
           select dst.kind as dstKind, dst.file_path as dstPath
           from edges e
@@ -3789,6 +3805,10 @@ class Both : public Base<char>, public Plain {}; // templated + plain in one cla
           'app/page.php must NOT mis-connect to unrelated lib/inc/db.php'
         ).toBeUndefined();
       } finally {
+        // Windows refuses to remove a directory holding an open file: both the
+        // graph's handle and this test's own one have to go first.
+        db?.close();
+        cg?.close();
         fs.rmSync(tempProject, { recursive: true, force: true });
       }
     });