diff --git a/CHANGELOG.md b/CHANGELOG.md
index beb756d7..59f72c8a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Changelog
 
+## 0.73.0 — 2026-10-03
+
+### runtime errorの収集: 対応しないOSは `unsupported` と答える
+
+- Windowsでは、`lattice runtime-errors snapshot`／`diagnostics` が `collection: "disabled"` を返していた。
+  設定が有効でも同じ答えで、「設定で止めている」のか「このOSでは収集できない」のかを区別できなかった。
+  Windowsでは `collection: "unsupported"` を返す。`status` は `not_applicable`、`cursor` は0、記録は空、
+  `diagnostics` のキーは今までと同じ。
+- 収集そのものは変わらない。Windowsではstoreの所有者と権限をPOSIXの形で確かめられないので、記録を作らない。
+- 受け側の前提: dotagents `49709de` 以降（`unsupported` を受け入れる）。
+
 ## 0.72.1 — 2026-10-03
 
 ### 修正
diff --git a/docs/01_integration-package.md b/docs/01_integration-package.md
index c9a45c57..2f65137e 100644
--- a/docs/01_integration-package.md
+++ b/docs/01_integration-package.md
@@ -225,6 +225,10 @@ native Windowsでは`HOST_PLATFORM_UNSUPPORTED`を返し、設定やstateへ書
   reporting（BugHub送信）はdotagents adapter所有で本storeは外部送信しない（collection/reporting分離）。
   固定catalog 5 code・fingerprint集約・cursor/ack・resolved+ack済み30日compact・POSIX owner-only検査で
   fail closed。正典は`src/runtime-errors.mjs`
+  - `diagnostics.collection`は`enabled`・`disabled`・`unsupported`の3値。`unsupported`は「このOSでは収集に
+    対応しない」という製品の答えで、Windowsが返す（storeの所有者と権限をPOSIXの形で確かめられない）。
+    設定が有効でも記録は作らない。`status`・`cursor`・配列・`diagnostics`のキーは`disabled`の時と同じ形
+    （`not_applicable`・すべて0・空）。受け側の前提はdotagents `49709de`以降。
   - 各記録は任意の`safe_context`を持つ: `command_kind`（落ちたCLIの面。`run.list`・`todo.start`等、
     Latticeが持つ一覧の語だけ。無ければ`other`）、`error_kind`（例外の種類。一覧に無ければ`other`）、
     `cause_code`（Nodeが付けるerror code。無ければ`none`）。付ける時は3つを必ずそろえる。
diff --git a/package-lock.json b/package-lock.json
index b8b2bb32..d05f0e34 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@quolu/lattice",
-  "version": "0.72.1",
+  "version": "0.73.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@quolu/lattice",
-      "version": "0.72.1",
+      "version": "0.73.0",
       "license": "PolyForm-Noncommercial-1.0.0",
       "dependencies": {
         "@clack/prompts": "^1.3.0",
diff --git a/package.json b/package.json
index 6f081be2..20858042 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@quolu/lattice",
-  "version": "0.72.1",
+  "version": "0.73.0",
   "description": "Schedulability compiler for multi-agent development: observe real code boundaries, refactor the conflicting seam, recompile the plan for parallel execution",
   "author": {
     "name": "Quo / クオ at kitepon.dev",
diff --git a/src/runtime-errors.mjs b/src/runtime-errors.mjs
index 9b538bfc..770c7539 100644
--- a/src/runtime-errors.mjs
+++ b/src/runtime-errors.mjs
@@ -76,7 +76,14 @@ function canonicalReporting(value) {
   return !value.enabled || (value.endpoint !== undefined && value.credential_file !== undefined);
 }
 
+// このOSで収集に対応するか。Windowsはstoreの所有者と権限をPOSIXの形で確かめられない（`ensureSafeDir`）ので
+// 対応しない。設定が有効でも記録は作らず、工場へは`disabled`でなく`unsupported`と答える——設定は有効なのに
+// 製品が黙って無効と答えると、受け側は故障と区別できない。
+const collectionSupported = (options = {}) => (options.platform ?? hostPlatform()) !== 'win32';
+const inactiveCollection = (options = {}) => (collectionSupported(options) ? 'disabled' : 'unsupported');
+
 function collectionEnabled(options = {}) {
+  if (!collectionSupported(options)) return false;
   const env = options.env ?? process.env;
   try {
     const path = options.configPath ?? defaultFactoryReporterConfigPath(env);
@@ -264,7 +271,7 @@ function snapshot(options = {}) {
     runtime_errors: rows.filter((record) => record.status === 'open').map(({ product_version, error_code, component, status, severity, fingerprint, message_template, count, first_seen, last_seen, state_schema_version, safe_context }) => ({ product_version, error_code, component, status, severity, fingerprint, message_template, occurrence_count: count, first_seen, last_seen, state_schema_version, ...(safe_context === undefined ? {} : { safe_context }) })),
     resolutions: rows.filter((record) => record.status === 'resolved').map(({ fingerprint, resolved_at, reason_code }) => ({ fingerprint, resolved_at, reason_code })),
     diagnostics: {
-      collection: enabled ? 'enabled' : 'disabled',
+      collection: enabled ? 'enabled' : inactiveCollection(options),
       status: enabled ? 'ready' : 'not_applicable',
       total_count: store.records.length,
       pending_count: store.records.filter((record) => record.sequence > store.acknowledged_through).length,
@@ -279,7 +286,7 @@ export function runtimeErrorsSnapshot(afterCursor = 0, limit = MAX_RECORDS, opti
 
 export function runtimeErrorsDiagnostics(options = {}) {
   if (!collectionEnabled(options)) {
-    return { schema: DIAGNOSTICS_SCHEMA, collection: 'disabled', status: 'not_applicable', total_count: 0, open_count: 0, pending_count: 0, high_watermark: 0, acknowledged_through: 0 };
+    return { schema: DIAGNOSTICS_SCHEMA, collection: inactiveCollection(options), status: 'not_applicable', total_count: 0, open_count: 0, pending_count: 0, high_watermark: 0, acknowledged_through: 0 };
   }
   try {
     const { path } = optionsFor(options);
@@ -300,7 +307,7 @@ export function runtimeErrorsDiagnostics(options = {}) {
 }
 
 export function recordRuntimeError(code, options = {}) {
-  if (!collectionEnabled(options)) return { status: 'disabled' };
+  if (!collectionEnabled(options)) return { status: inactiveCollection(options) };
   const definition = definitions[code];
   if (!definition) throw Error('unknown_runtime_code');
   const { path } = optionsFor(options);
diff --git a/test/integration/hold-resume.integration.mjs b/test/integration/hold-resume.integration.mjs
index 9566662b..d749b60c 100644
--- a/test/integration/hold-resume.integration.mjs
+++ b/test/integration/hold-resume.integration.mjs
@@ -67,8 +67,11 @@ test('競合群の後継を先に起動し、無関係workerの旧epoch成果を
     await writeFile(path.join(repoRoot, 'test', `${symbol}.test.mjs`), unitTest(symbol));
   }
   // T2が宣言外のsrc/alpha.mjs——T1のscope——へも書く。T3は無関係なのでcontinue_setへ落ちる。
+  // `hold_ms`はworkerが書いた後に走り続ける時間で、holdはこの窓の中で届かなければならない。10秒では、
+  // 混んだ機械で窓が先に閉じ、holdが`worker processを止められない`（ESRCH）で断られる。30秒は、2コアに
+  // CPU負荷16本を重ねた状態で通ることを確かめた値。
   await writeFile(path.join(repoRoot, 'adapter-config.json'),
-    `${JSON.stringify({ mode: 'deterministic', hold_ms: 10_000,
+    `${JSON.stringify({ mode: 'deterministic', hold_ms: 30_000,
       extra_writes_by_todo: { T2: ['src/alpha.mjs'] } })}\n`);
 
   const git = (...args) => ok(invoke('git', ['-c', 'user.email=a@example.invalid',
diff --git a/test/runtime-errors-platform.test.mjs b/test/runtime-errors-platform.test.mjs
new file mode 100644
index 00000000..eeaf43a6
--- /dev/null
+++ b/test/runtime-errors-platform.test.mjs
@@ -0,0 +1,56 @@
+import assert from 'node:assert/strict';
+import { execFile } from 'node:child_process';
+import { existsSync } from 'node:fs';
+import { mkdtemp, mkdir, writeFile, rm } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import { fileURLToPath } from 'node:url';
+import { promisify } from 'node:util';
+
+// `runtime-errors.test.mjs`はWindowsで全件skipする。この試験はどのOSでも走り、そのOSで実際に
+// CLIが返す答えを確かめる——Windowsは`unsupported`、ほかは設定に従う。
+const execFileAsync = promisify(execFile);
+const cliPath = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..', 'bin', 'lattice.mjs');
+const windows = process.platform === 'win32';
+const VALID_CONFIG = {
+  schema_version: '1.0',
+  host: { id: 'test-host', profile: windows ? 'windows-native' : 'linux' },
+  collection: { enabled: true },
+  reporting: { enabled: false },
+};
+
+async function runJson(args, env) {
+  const { stdout } = await execFileAsync(process.execPath, [cliPath, 'runtime-errors', ...args, '--json'], { env });
+  return JSON.parse(stdout.trim());
+}
+
+test('CLIは収集に対応しないOSでunsupported、対応するOSでは設定どおりに答える', async () => {
+  const root = await mkdtemp(path.join(os.tmpdir(), 'lattice-rterr-platform-'));
+  try {
+    const env = { ...process.env, HOME: root, USERPROFILE: root,
+      XDG_CONFIG_HOME: path.join(root, 'xdg-config'), XDG_STATE_HOME: path.join(root, 'xdg-state') };
+
+    // 設定が無い時: 対応するOSは`disabled`、対応しないOSは`unsupported`。
+    const inactive = windows ? 'unsupported' : 'disabled';
+    const bare = await runJson(['snapshot'], env);
+    assert.deepEqual(bare.diagnostics,
+      { collection: inactive, status: 'not_applicable', total_count: 0, pending_count: 0, truncated: false });
+    assert.equal((await runJson(['diagnostics'], env)).collection, inactive);
+
+    // 設定が有効な時: 対応しないOSは、それでも`unsupported`のまま記録を作らない。
+    await mkdir(path.join(root, 'xdg-config', 'dotagents'), { recursive: true });
+    await writeFile(path.join(root, 'xdg-config', 'dotagents', 'factory-reporter.json'), JSON.stringify(VALID_CONFIG));
+    const configured = await runJson(['snapshot'], env);
+    assert.equal(configured.diagnostics.collection, windows ? 'unsupported' : 'enabled');
+    assert.equal(configured.diagnostics.status, windows ? 'not_applicable' : 'ready');
+    assert.deepEqual(configured.cursor, { high_watermark: 0, acknowledged_through: 0, next: 0 });
+    assert.deepEqual(configured.runtime_errors, []);
+    assert.deepEqual(configured.resolutions, []);
+    assert.deepEqual(Object.keys(configured.diagnostics),
+      ['collection', 'status', 'total_count', 'pending_count', 'truncated']);
+    if (windows) assert.equal(existsSync(path.join(root, 'xdg-state', 'lattice')), false);
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
diff --git a/test/runtime-errors.test.mjs b/test/runtime-errors.test.mjs
index 7c1b430e..2d0c3906 100644
--- a/test/runtime-errors.test.mjs
+++ b/test/runtime-errors.test.mjs
@@ -92,6 +92,29 @@ test('工場が名乗るhost profileはすべて収集を有効にし、未知
   }
 });
 
+test('収集に対応しないOSでは、設定が有効でもunsupportedと答えstateへ触れない', async () => {
+  const workspace = await makeWorkspace();
+  const options = { ...workspace.options, platform: 'win32' };
+  try {
+    assert.deepEqual(recordRuntimeError('LATTICE.CLI_INTERNAL_FAILED', options), { status: 'unsupported' });
+    const snapshot = runtimeErrorsSnapshot(0, 256, options);
+    // 工場（dotagents）が`unsupported`に課す形: status・cursor・配列・diagnosticsのキーは`disabled`の時と同じ。
+    assert.deepEqual(snapshot.diagnostics,
+      { collection: 'unsupported', status: 'not_applicable', total_count: 0, pending_count: 0, truncated: false });
+    assert.deepEqual(snapshot.cursor, { high_watermark: 0, acknowledged_through: 0, next: 0 });
+    assert.deepEqual(snapshot.runtime_errors, []);
+    assert.deepEqual(snapshot.resolutions, []);
+    const diagnostics = runtimeErrorsDiagnostics(options);
+    assert.equal(diagnostics.collection, 'unsupported');
+    assert.equal(diagnostics.status, 'not_applicable');
+    assert.equal(existsSync(path.dirname(workspace.storePath)), false);
+    // 同じ設定でも、対応するOSでは有効と答える。
+    assert.equal(runtimeErrorsDiagnostics({ ...workspace.options, platform: 'linux' }).collection, 'enabled');
+  } finally {
+    await rm(workspace.root, { recursive: true, force: true });
+  }
+});
+
 test('同一原因はfingerprint集約でcount/last_seen/sequenceと発生版が進む', async () => {
   const workspace = await makeWorkspace();
   try {