diff --git a/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js b/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js
index afb0b76d5..14937bccc 100644
--- a/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js
+++ b/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js
@@ -108,12 +108,17 @@ export function installResponseCompression({ matches = () => true } = {}) {
     }
     function flush(res) {
         const pending = take(res);
-        if (pending !== undefined && !res.destroyed)
-            origWriteHead.apply(res, pending.args);
+        if (pending === undefined || res.destroyed) return false;
+        origWriteHead.apply(res, pending.args);
+        return true;
     }
     function patchedWriteHead(...args) {
-        flush(this);
+        const flushed = flush(this);
         const raw = typeof args[1] === 'string' ? args[2] : args[1];
+        // This call committed the deferred header write: a status-only re-entry is
+        // the middleware's implicit head write and must stay a no-op, matching
+        // Node's _implicitHeader once _header is set.
+        if (flushed && raw === undefined) return this;
         // Raw header arrays, including duplicate headers, keep Node's exact path.
         if (Array.isArray(raw) || (raw !== undefined && (raw === null || typeof raw !== 'object')))
             return origWriteHead.apply(this, args);
diff --git a/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js.map b/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js.map
index c946405c8..1d3449d95 100644
--- a/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js.map
+++ b/app/src/main/assets/builtin-plugins/dsh-web-mobile/lib/compress.js.map
@@ -1 +1 @@
-{"version":3,"file":"compress.js","sourceRoot":"","sources":["dsha://tools/mobile-server/compress.js"],"sourcesContent":["/**\n * DSHA bounded compression for complete JSON responses.\n * Only a single end(data) can be compressed. Every write() is delegated at\n * once, with its original encoding, callback and backpressure. Headers alone\n * may wait one event-loop turn; no response body is ever accumulated here.\n * SSE, HEAD, already encoded bodies and oversized JSON remain native streams.\n */\nimport { brotliCompress, constants as zlibConstants, gzip } from 'node:zlib';\nimport { ServerResponse as NodeServerResponse } from 'node:http';\n\nconst MIN_JSON_BYTES = 4 * 1024;\nexport const MAX_JSON_BYTES = 1024 * 1024;\nexport const MAX_COMPRESSIONS = 2;\nlet inflight = 0;\nconst deferred = new WeakMap();\n\nexport function headerValue(headers, name) {\n    const key = Object.keys(headers).find(key => key.toLowerCase() === name);\n    return key === undefined ? undefined : String(headers[key]);\n}\nexport function isDeferrable(headers) {\n    return headerValue(headers, 'content-encoding') === undefined\n        && /(?:^|\\s|;)application\\/(?:[\\w.+-]+\\+)?json(?:\\s*;|$)/i.test(headerValue(headers, 'content-type') ?? '')\n        && !/\\bno-transform\\b/i.test(headerValue(headers, 'cache-control') ?? '')\n        && headerValue(headers, 'content-range') === undefined\n        && headerValue(headers, 'transfer-encoding') === undefined\n        && headerValue(headers, 'content-md5') === undefined\n        && !/^\"/.test(headerValue(headers, 'etag') ?? '');\n}\nexport function varyWithAcceptEncoding(headers) {\n    const key = Object.keys(headers).find(key => key.toLowerCase() === 'vary') ?? 'vary';\n    const value = String(headers[key] ?? '');\n    if (!value.split(',').some(token => /^(?:accept-encoding|\\*)$/i.test(token.trim())))\n        headers[key] = value ? `${value}, Accept-Encoding` : 'Accept-Encoding';\n}\nfunction pickEncoding(res) {\n    const values = new Map();\n    for (const part of String(res.req?.headers['accept-encoding'] ?? '').split(',')) {\n        const [name, ...params] = part.trim().toLowerCase().split(';');\n        const q = params.find(value => /^\\s*q\\s*=/.test(value));\n        const quality = q === undefined ? 1 : Number(q.split('=')[1]);\n        values.set(name, Number.isFinite(quality) && quality >= 0 && quality <= 1 ? quality : 0);\n    }\n    const br = values.get('br') ?? values.get('*') ?? 0;\n    const gzip = values.get('gzip') ?? values.get('*') ?? 0;\n    return br > 0 && br >= gzip ? 'br' : gzip > 0 ? 'gzip' : null;\n}\nfunction hasBody(res, status = res.statusCode) {\n    return res.req?.method !== 'HEAD' && status >= 200 && ![204, 205, 206, 304].includes(status);\n}\nfunction snapshotHeaders(headers) {\n    return Object.fromEntries(Object.entries(headers).map(([key, value]) => [key, Array.isArray(value) ? value.slice() : value]));\n}\nfunction mergedHeaders(base, overlay) {\n    const headers = { ...base };\n    for (const [name, value] of Object.entries(overlay)) {\n        for (const key of Object.keys(headers))\n            if (key.toLowerCase() === name.toLowerCase()) delete headers[key];\n        headers[name] = value;\n    }\n    return headers;\n}\n\nexport function installResponseCompression({ matches = () => true } = {}) {\n    const proto = NodeServerResponse.prototype;\n    const origWriteHead = proto.writeHead;\n    const origWrite = proto.write;\n    const origEnd = proto.end;\n    const origFlushHeaders = proto.flushHeaders;\n    const active = new Set();\n    const nativeBody = new WeakSet();\n    function delegate(method, res, args) {\n        nativeBody.add(res);\n        try { return method.apply(res, args); }\n        finally { nativeBody.delete(res); }\n    }\n    function belongs(res) {\n        try { return matches(res.req, res) === true; }\n        catch { return false; }\n    }\n    // end() has accepted the complete body while libuv compresses it. Keep\n    // Node's public end guard so a subsequent write/end follows its native\n    // error path. Do not change any private stream/socket fields. The false\n    // writableFinished view lasts only until the compressed native end.\n    function reserveEnd(res) {\n        const finished = Object.getOwnPropertyDescriptor(res, 'finished');\n        if (!finished?.configurable || !finished.writable || finished.value !== false\n            || Object.hasOwn(res, 'writableFinished')) return undefined;\n        let value = finished.value;\n        Object.defineProperty(res, 'finished', { configurable: true, enumerable: finished.enumerable,\n            get: () => true, set: next => { value = next; } });\n        Object.defineProperty(res, 'writableFinished', { configurable: true, get: () => false });\n        return (closed = false) => {\n            Object.defineProperty(res, 'finished', { ...finished, value: closed || value });\n            delete res.writableFinished;\n        };\n    }\n\n    function take(res) {\n        const pending = deferred.get(res);\n        if (pending !== undefined) {\n            deferred.delete(res);\n            active.delete(res);\n            clearImmediate(pending.timer);\n            res.off('close', pending.onClose);\n        }\n        return pending;\n    }\n    function flush(res) {\n        const pending = take(res);\n        if (pending !== undefined && !res.destroyed)\n            origWriteHead.apply(res, pending.args);\n    }\n    function patchedWriteHead(...args) {\n        flush(this);\n        const raw = typeof args[1] === 'string' ? args[2] : args[1];\n        // Raw header arrays, including duplicate headers, keep Node's exact path.\n        if (Array.isArray(raw) || (raw !== undefined && (raw === null || typeof raw !== 'object')))\n            return origWriteHead.apply(this, args);\n        const headers = mergedHeaders(this.getHeaders(), raw ?? {});\n        if (!belongs(this) || nativeBody.has(this) || this.headersSent || !hasBody(this, Number(args[0])) || !isDeferrable(headers) || pickEncoding(this) === null)\n            return origWriteHead.apply(this, args);\n        // Use Node itself to validate all overloads/status/header values now,\n        // rather than deferring a native exception into an unrelated timer.\n        const validation = new NodeServerResponse(this.req);\n        for (const [name, value] of Object.entries(this.getHeaders())) validation.setHeader(name, value);\n        const copied = args.slice();\n        if (raw !== undefined) copied[typeof args[1] === 'string' ? 2 : 1] = snapshotHeaders(raw);\n        origWriteHead.apply(validation, copied);\n        this.statusCode = validation.statusCode;\n        this.statusMessage = validation.statusMessage;\n        const pending = { args: copied, headers: raw === undefined ? {} : copied[typeof args[1] === 'string' ? 2 : 1] };\n        pending.onClose = () => take(this);\n        pending.timer = setImmediate(() => flush(this));\n        deferred.set(this, pending);\n        active.add(this);\n        this.once('close', pending.onClose);\n        return this;\n    }\n    function patchedWrite(...args) {\n        flush(this);\n        return delegate(origWrite, this, args);\n    }\n    function patchedFlushHeaders(...args) {\n        flush(this);\n        return delegate(origFlushHeaders, this, args);\n    }\n    function patchedEnd(...args) {\n        const pending = deferred.get(this);\n        const headers = mergedHeaders(this.getHeaders(), pending?.headers ?? {});\n        const encoding = pickEncoding(this);\n        const chunk = args[0];\n        const textEncoding = typeof args[1] === 'string' ? args[1] : undefined;\n        let body;\n        const validEncodingArgument = args[1] === undefined || typeof args[1] === 'string' || typeof args[1] === 'function';\n        const validCallbackArgument = typeof args[1] === 'function' || args[2] === undefined || typeof args[2] === 'function';\n        if (belongs(this) && inflight < MAX_COMPRESSIONS && !this.finished && !this.headersSent && !this.destroyed && !this.strictContentLength && validEncodingArgument && validCallbackArgument && hasBody(this) && isDeferrable(headers) && encoding !== null) {\n            if (typeof chunk === 'string') {\n                // Preserve invalid-encoding errors through the native end path.\n                if (textEncoding === undefined || Buffer.isEncoding(textEncoding)) {\n                    const bytes = Buffer.byteLength(chunk, textEncoding);\n                    if (bytes >= MIN_JSON_BYTES && bytes <= MAX_JSON_BYTES) body = Buffer.from(chunk, textEncoding);\n                }\n            } else if (chunk instanceof Uint8Array && chunk.byteLength >= MIN_JSON_BYTES && chunk.byteLength <= MAX_JSON_BYTES) {\n                body = Buffer.from(chunk);\n            }\n        }\n        if (body === undefined) {\n            flush(this);\n            return delegate(origEnd, this, args);\n        }\n        const restoreEnd = reserveEnd(this);\n        if (restoreEnd === undefined) {\n            flush(this);\n            return delegate(origEnd, this, args);\n        }\n        take(this);\n        for (const key of Object.keys(headers))\n            if (key.toLowerCase() === 'content-length') delete headers[key];\n        headers['content-encoding'] = encoding;\n        varyWithAcceptEncoding(headers);\n        this.removeHeader('content-length');\n        // Commit the selected representation now. Its size is not known until\n        // the worker finishes, so Node supplies its native chunked boundary.\n        // This also preserves synchronous header validation and headersSent.\n        try { origWriteHead.call(this, this.statusCode, this.statusMessage, headers); }\n        catch (error) { restoreEnd(); throw error; }\n        const callback = typeof args[1] === 'function' ? args[1] : args[2];\n        let called = false, complete = false;\n        const done = error => {\n            if (called) return;\n            called = true;\n            if (typeof callback === 'function') callback(error);\n        };\n        const finish = (error, compressed) => {\n            if (complete) return;\n            complete = true;\n            this.off('close', onClose);\n            restoreEnd(Boolean(error) || this.destroyed);\n            if (error || this.destroyed) {\n                const failure = error ?? Object.assign(new Error('response closed during compression'), { code: 'ERR_STREAM_PREMATURE_CLOSE' });\n                this.destroy(failure);\n                queueMicrotask(() => done(failure));\n                return;\n            }\n            // The original encoding was consumed by Buffer.from; only end's\n            // callback remains. Node still owns socket writes/backpressure.\n            origEnd.call(this, compressed, done);\n        };\n        const onClose = () => finish();\n        this.once('close', onClose);\n        inflight++;\n        const compressed = (error, bytes) => { inflight--; finish(error, bytes); };\n        try {\n            if (encoding === 'br') brotliCompress(body, { params: { [zlibConstants.BROTLI_PARAM_QUALITY]: 4 } }, compressed);\n            else gzip(body, { level: 4 }, compressed);\n        } catch (error) { inflight--; finish(error); }\n        return this;\n    }\n    proto.writeHead = patchedWriteHead;\n    proto.write = patchedWrite;\n    proto.end = patchedEnd;\n    proto.flushHeaders = patchedFlushHeaders;\n    return () => {\n        for (const res of active) flush(res);\n        // Already accepted end bodies retain their worker and callback until\n        // completion. Unload restores the hook immediately and never cancels\n        // or resends a response that another route still owns.\n        if (proto.writeHead === patchedWriteHead) proto.writeHead = origWriteHead;\n        if (proto.write === patchedWrite) proto.write = origWrite;\n        if (proto.end === patchedEnd) proto.end = origEnd;\n        if (proto.flushHeaders === patchedFlushHeaders) proto.flushHeaders = origFlushHeaders;\n    };\n}\n//# sourceMappingURL=compress.js.map\n"],"names":[],"mappings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}
+{"version":3,"file":"compress.js","sourceRoot":"","sources":["dsha://tools/mobile-server/compress.js"],"sourcesContent":["/**\n * DSHA bounded compression for complete JSON responses.\n * Only a single end(data) can be compressed. Every write() is delegated at\n * once, with its original encoding, callback and backpressure. Headers alone\n * may wait one event-loop turn; no response body is ever accumulated here.\n * SSE, HEAD, already encoded bodies and oversized JSON remain native streams.\n */\nimport { brotliCompress, constants as zlibConstants, gzip } from 'node:zlib';\nimport { ServerResponse as NodeServerResponse } from 'node:http';\n\nconst MIN_JSON_BYTES = 4 * 1024;\nexport const MAX_JSON_BYTES = 1024 * 1024;\nexport const MAX_COMPRESSIONS = 2;\nlet inflight = 0;\nconst deferred = new WeakMap();\n\nexport function headerValue(headers, name) {\n    const key = Object.keys(headers).find(key => key.toLowerCase() === name);\n    return key === undefined ? undefined : String(headers[key]);\n}\nexport function isDeferrable(headers) {\n    return headerValue(headers, 'content-encoding') === undefined\n        && /(?:^|\\s|;)application\\/(?:[\\w.+-]+\\+)?json(?:\\s*;|$)/i.test(headerValue(headers, 'content-type') ?? '')\n        && !/\\bno-transform\\b/i.test(headerValue(headers, 'cache-control') ?? '')\n        && headerValue(headers, 'content-range') === undefined\n        && headerValue(headers, 'transfer-encoding') === undefined\n        && headerValue(headers, 'content-md5') === undefined\n        && !/^\"/.test(headerValue(headers, 'etag') ?? '');\n}\nexport function varyWithAcceptEncoding(headers) {\n    const key = Object.keys(headers).find(key => key.toLowerCase() === 'vary') ?? 'vary';\n    const value = String(headers[key] ?? '');\n    if (!value.split(',').some(token => /^(?:accept-encoding|\\*)$/i.test(token.trim())))\n        headers[key] = value ? `${value}, Accept-Encoding` : 'Accept-Encoding';\n}\nfunction pickEncoding(res) {\n    const values = new Map();\n    for (const part of String(res.req?.headers['accept-encoding'] ?? '').split(',')) {\n        const [name, ...params] = part.trim().toLowerCase().split(';');\n        const q = params.find(value => /^\\s*q\\s*=/.test(value));\n        const quality = q === undefined ? 1 : Number(q.split('=')[1]);\n        values.set(name, Number.isFinite(quality) && quality >= 0 && quality <= 1 ? quality : 0);\n    }\n    const br = values.get('br') ?? values.get('*') ?? 0;\n    const gzip = values.get('gzip') ?? values.get('*') ?? 0;\n    return br > 0 && br >= gzip ? 'br' : gzip > 0 ? 'gzip' : null;\n}\nfunction hasBody(res, status = res.statusCode) {\n    return res.req?.method !== 'HEAD' && status >= 200 && ![204, 205, 206, 304].includes(status);\n}\nfunction snapshotHeaders(headers) {\n    return Object.fromEntries(Object.entries(headers).map(([key, value]) => [key, Array.isArray(value) ? value.slice() : value]));\n}\nfunction mergedHeaders(base, overlay) {\n    const headers = { ...base };\n    for (const [name, value] of Object.entries(overlay)) {\n        for (const key of Object.keys(headers))\n            if (key.toLowerCase() === name.toLowerCase()) delete headers[key];\n        headers[name] = value;\n    }\n    return headers;\n}\n\nexport function installResponseCompression({ matches = () => true } = {}) {\n    const proto = NodeServerResponse.prototype;\n    const origWriteHead = proto.writeHead;\n    const origWrite = proto.write;\n    const origEnd = proto.end;\n    const origFlushHeaders = proto.flushHeaders;\n    const active = new Set();\n    const nativeBody = new WeakSet();\n    function delegate(method, res, args) {\n        nativeBody.add(res);\n        try { return method.apply(res, args); }\n        finally { nativeBody.delete(res); }\n    }\n    function belongs(res) {\n        try { return matches(res.req, res) === true; }\n        catch { return false; }\n    }\n    // end() has accepted the complete body while libuv compresses it. Keep\n    // Node's public end guard so a subsequent write/end follows its native\n    // error path. Do not change any private stream/socket fields. The false\n    // writableFinished view lasts only until the compressed native end.\n    function reserveEnd(res) {\n        const finished = Object.getOwnPropertyDescriptor(res, 'finished');\n        if (!finished?.configurable || !finished.writable || finished.value !== false\n            || Object.hasOwn(res, 'writableFinished')) return undefined;\n        let value = finished.value;\n        Object.defineProperty(res, 'finished', { configurable: true, enumerable: finished.enumerable,\n            get: () => true, set: next => { value = next; } });\n        Object.defineProperty(res, 'writableFinished', { configurable: true, get: () => false });\n        return (closed = false) => {\n            Object.defineProperty(res, 'finished', { ...finished, value: closed || value });\n            delete res.writableFinished;\n        };\n    }\n\n    function take(res) {\n        const pending = deferred.get(res);\n        if (pending !== undefined) {\n            deferred.delete(res);\n            active.delete(res);\n            clearImmediate(pending.timer);\n            res.off('close', pending.onClose);\n        }\n        return pending;\n    }\n    function flush(res) {\n        const pending = take(res);\n        if (pending === undefined || res.destroyed) return false;\n        origWriteHead.apply(res, pending.args);\n        return true;\n    }\n    function patchedWriteHead(...args) {\n        const flushed = flush(this);\n        const raw = typeof args[1] === 'string' ? args[2] : args[1];\n        // This call committed the deferred header write: a status-only re-entry is\n        // the middleware's implicit head write and must stay a no-op, matching\n        // Node's _implicitHeader once _header is set.\n        if (flushed && raw === undefined) return this;\n        // Raw header arrays, including duplicate headers, keep Node's exact path.\n        if (Array.isArray(raw) || (raw !== undefined && (raw === null || typeof raw !== 'object')))\n            return origWriteHead.apply(this, args);\n        const headers = mergedHeaders(this.getHeaders(), raw ?? {});\n        if (!belongs(this) || nativeBody.has(this) || this.headersSent || !hasBody(this, Number(args[0])) || !isDeferrable(headers) || pickEncoding(this) === null)\n            return origWriteHead.apply(this, args);\n        // Use Node itself to validate all overloads/status/header values now,\n        // rather than deferring a native exception into an unrelated timer.\n        const validation = new NodeServerResponse(this.req);\n        for (const [name, value] of Object.entries(this.getHeaders())) validation.setHeader(name, value);\n        const copied = args.slice();\n        if (raw !== undefined) copied[typeof args[1] === 'string' ? 2 : 1] = snapshotHeaders(raw);\n        origWriteHead.apply(validation, copied);\n        this.statusCode = validation.statusCode;\n        this.statusMessage = validation.statusMessage;\n        const pending = { args: copied, headers: raw === undefined ? {} : copied[typeof args[1] === 'string' ? 2 : 1] };\n        pending.onClose = () => take(this);\n        pending.timer = setImmediate(() => flush(this));\n        deferred.set(this, pending);\n        active.add(this);\n        this.once('close', pending.onClose);\n        return this;\n    }\n    function patchedWrite(...args) {\n        flush(this);\n        return delegate(origWrite, this, args);\n    }\n    function patchedFlushHeaders(...args) {\n        flush(this);\n        return delegate(origFlushHeaders, this, args);\n    }\n    function patchedEnd(...args) {\n        const pending = deferred.get(this);\n        const headers = mergedHeaders(this.getHeaders(), pending?.headers ?? {});\n        const encoding = pickEncoding(this);\n        const chunk = args[0];\n        const textEncoding = typeof args[1] === 'string' ? args[1] : undefined;\n        let body;\n        const validEncodingArgument = args[1] === undefined || typeof args[1] === 'string' || typeof args[1] === 'function';\n        const validCallbackArgument = typeof args[1] === 'function' || args[2] === undefined || typeof args[2] === 'function';\n        if (belongs(this) && inflight < MAX_COMPRESSIONS && !this.finished && !this.headersSent && !this.destroyed && !this.strictContentLength && validEncodingArgument && validCallbackArgument && hasBody(this) && isDeferrable(headers) && encoding !== null) {\n            if (typeof chunk === 'string') {\n                // Preserve invalid-encoding errors through the native end path.\n                if (textEncoding === undefined || Buffer.isEncoding(textEncoding)) {\n                    const bytes = Buffer.byteLength(chunk, textEncoding);\n                    if (bytes >= MIN_JSON_BYTES && bytes <= MAX_JSON_BYTES) body = Buffer.from(chunk, textEncoding);\n                }\n            } else if (chunk instanceof Uint8Array && chunk.byteLength >= MIN_JSON_BYTES && chunk.byteLength <= MAX_JSON_BYTES) {\n                body = Buffer.from(chunk);\n            }\n        }\n        if (body === undefined) {\n            flush(this);\n            return delegate(origEnd, this, args);\n        }\n        const restoreEnd = reserveEnd(this);\n        if (restoreEnd === undefined) {\n            flush(this);\n            return delegate(origEnd, this, args);\n        }\n        take(this);\n        for (const key of Object.keys(headers))\n            if (key.toLowerCase() === 'content-length') delete headers[key];\n        headers['content-encoding'] = encoding;\n        varyWithAcceptEncoding(headers);\n        this.removeHeader('content-length');\n        // Commit the selected representation now. Its size is not known until\n        // the worker finishes, so Node supplies its native chunked boundary.\n        // This also preserves synchronous header validation and headersSent.\n        try { origWriteHead.call(this, this.statusCode, this.statusMessage, headers); }\n        catch (error) { restoreEnd(); throw error; }\n        const callback = typeof args[1] === 'function' ? args[1] : args[2];\n        let called = false, complete = false;\n        const done = error => {\n            if (called) return;\n            called = true;\n            if (typeof callback === 'function') callback(error);\n        };\n        const finish = (error, compressed) => {\n            if (complete) return;\n            complete = true;\n            this.off('close', onClose);\n            restoreEnd(Boolean(error) || this.destroyed);\n            if (error || this.destroyed) {\n                const failure = error ?? Object.assign(new Error('response closed during compression'), { code: 'ERR_STREAM_PREMATURE_CLOSE' });\n                this.destroy(failure);\n                queueMicrotask(() => done(failure));\n                return;\n            }\n            // The original encoding was consumed by Buffer.from; only end's\n            // callback remains. Node still owns socket writes/backpressure.\n            origEnd.call(this, compressed, done);\n        };\n        const onClose = () => finish();\n        this.once('close', onClose);\n        inflight++;\n        const compressed = (error, bytes) => { inflight--; finish(error, bytes); };\n        try {\n            if (encoding === 'br') brotliCompress(body, { params: { [zlibConstants.BROTLI_PARAM_QUALITY]: 4 } }, compressed);\n            else gzip(body, { level: 4 }, compressed);\n        } catch (error) { inflight--; finish(error); }\n        return this;\n    }\n    proto.writeHead = patchedWriteHead;\n    proto.write = patchedWrite;\n    proto.end = patchedEnd;\n    proto.flushHeaders = patchedFlushHeaders;\n    return () => {\n        for (const res of active) flush(res);\n        // Already accepted end bodies retain their worker and callback until\n        // completion. Unload restores the hook immediately and never cancels\n        // or resends a response that another route still owns.\n        if (proto.writeHead === patchedWriteHead) proto.writeHead = origWriteHead;\n        if (proto.write === patchedWrite) proto.write = origWrite;\n        if (proto.end === patchedEnd) proto.end = origEnd;\n        if (proto.flushHeaders === patchedFlushHeaders) proto.flushHeaders = origFlushHeaders;\n    };\n}\n//# sourceMappingURL=compress.js.map\n"],"names":[],"mappings":"AAAA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA;AACA"}
diff --git a/tools/mobile-server/compress.js b/tools/mobile-server/compress.js
index afb0b76d5..14937bccc 100644
--- a/tools/mobile-server/compress.js
+++ b/tools/mobile-server/compress.js
@@ -108,12 +108,17 @@ export function installResponseCompression({ matches = () => true } = {}) {
     }
     function flush(res) {
         const pending = take(res);
-        if (pending !== undefined && !res.destroyed)
-            origWriteHead.apply(res, pending.args);
+        if (pending === undefined || res.destroyed) return false;
+        origWriteHead.apply(res, pending.args);
+        return true;
     }
     function patchedWriteHead(...args) {
-        flush(this);
+        const flushed = flush(this);
         const raw = typeof args[1] === 'string' ? args[2] : args[1];
+        // This call committed the deferred header write: a status-only re-entry is
+        // the middleware's implicit head write and must stay a no-op, matching
+        // Node's _implicitHeader once _header is set.
+        if (flushed && raw === undefined) return this;
         // Raw header arrays, including duplicate headers, keep Node's exact path.
         if (Array.isArray(raw) || (raw !== undefined && (raw === null || typeof raw !== 'object')))
             return origWriteHead.apply(this, args);
diff --git a/tools/test-mobile-server-streams.mjs b/tools/test-mobile-server-streams.mjs
index 1f7b50ec4..124bed9d8 100644
--- a/tools/test-mobile-server-streams.mjs
+++ b/tools/test-mobile-server-streams.mjs
@@ -274,3 +274,44 @@ test('writeHead validates native status/header errors synchronously; callback er
     assert.equal(callbackError, 'ERR_STREAM_WRITE_AFTER_END'); assert.equal(responseError, callbackError);
   });
 });
+
+test('host gzip wrapper: implicit writeHead after deferred headers stays a no-op', async () => {
+  // 宿主 compression 的 on-headers 包装：把 writeHead 的头部并入响应头表，只把
+  // statusCode 传给下一层；compression 的 end 代理在头未发出时补一次隐式 writeHead。
+  // 小 JSON + Content-Length 低于宿主压缩阈值时，这条路径会走延迟分支。
+  const body = JSON.stringify({ ok: true, note: 'y'.repeat(100) });
+  let failure;
+  await fixture((_req, res) => {
+    const writeHead = res.writeHead;
+    res.writeHead = function (statusCode, reasonOrHeaders, headers) {
+      const raw = typeof reasonOrHeaders === 'string' ? headers : reasonOrHeaders;
+      if (raw !== undefined && raw !== null && typeof raw === 'object' && !Array.isArray(raw)) {
+        for (const [name, value] of Object.entries(raw)) this.setHeader(name, value);
+      }
+      return writeHead.call(this, statusCode, ...(typeof reasonOrHeaders === 'string' ? [reasonOrHeaders] : []));
+    };
+    const end = res.end;
+    res.end = function (...args) {
+      if (!this.headersSent) this.writeHead(this.statusCode);
+      return end.apply(this, args);
+    };
+    try {
+      res.writeHead(200, {
+        'Content-Type': 'application/json; charset=utf-8',
+        'Content-Length': Buffer.byteLength(body),
+        'Cache-Control': 'no-store',
+      });
+      res.end(body);
+    } catch (error) {
+      failure = error;
+      res.destroy();
+    }
+  }, async port => {
+    const result = await fetch(port).catch(error => ({ error }));
+    assert.equal(failure, undefined, failure && `${failure.code}: ${failure.message}`);
+    assert.ok(!('error' in result), 'the response must complete');
+    assert.equal(result.body.toString(), body);
+    assert.equal(result.res.headers['content-length'], String(Buffer.byteLength(body)));
+    assert.equal(result.res.headers['content-encoding'], undefined);
+  });
+});