feat(docker): replace logs modal with dedicated xterm page

Address PR review feedback by moving container logs to a full-page viewer
using xterm (matching /manage/tools/logs), with per-row actions for better
UX when browsing long container lists. Harden log streaming with multiplex
decode fallbacks, stream cleanup on parse errors, and decode unit tests.

packages/request-handler/src/docker-log-decode.ts

@@ -0,0 +1,89 @@
+const DOCKER_STREAM_HEADER_SIZE = 8;
+const DOCKER_STREAM_TYPES = new Set([1, 2]);
+
+export const decodeDockerLogs = (logs: Buffer | string) => {
+  if (typeof logs === "string") {
+    return logs;
+  }
+
+  if (logs.length === 0) {
+    return "";
+  }
+
+  let cursor = 0;
+  const parts: string[] = [];
+
+  while (cursor < logs.length) {
+    if (cursor + DOCKER_STREAM_HEADER_SIZE > logs.length) {
+      break;
+    }
+
+    const streamType = logs.readUInt8(cursor);
+    if (!DOCKER_STREAM_TYPES.has(streamType)) {
+      return logs.toString("utf-8");
+    }
+
+    const length = logs.readUInt32BE(cursor + 4);
+    const start = cursor + DOCKER_STREAM_HEADER_SIZE;
+    const end = start + length;
+    if (end > logs.length) {
+      break;
+    }
+
+    parts.push(logs.subarray(start, end).toString("utf-8"));
+    cursor = end;
+  }
+
+  const decoded = parts.join("");
+  if (decoded.length === 0) {
+    return logs.toString("utf-8");
+  }
+
+  return decoded;
+};
+
+export const createDockerLogStreamProcessor = (
+  onData: (data: string) => void,
+  onError: (err: Error) => void,
+  maxMessageSize: number,
+) => {
+  let buffer = Buffer.alloc(0);
+
+  const processChunk = (chunk: Buffer) => {
+    buffer = Buffer.concat([buffer, chunk]);
+
+    while (buffer.length > 0) {
+      if (buffer.length < DOCKER_STREAM_HEADER_SIZE) {
+        break;
+      }
+
+      const streamType = buffer.readUInt8(0);
+      if (!DOCKER_STREAM_TYPES.has(streamType)) {
+        onData(buffer.toString("utf-8"));
+        buffer = Buffer.alloc(0);
+        break;
+      }
+
+      const length = buffer.readUInt32BE(4);
+      if (length > maxMessageSize) {
+        onError(
+          new Error(`Docker log message size (${length} bytes) exceeds maximum allowed (${maxMessageSize} bytes)`),
+        );
+        return false;
+      }
+
+      const fullMessageSize = DOCKER_STREAM_HEADER_SIZE + length;
+      if (buffer.length < fullMessageSize) {
+        break;
+      }
+
+      const payload = buffer.subarray(DOCKER_STREAM_HEADER_SIZE, fullMessageSize);
+      onData(payload.toString("utf-8"));
+      buffer = buffer.subarray(fullMessageSize);
+    }
+
+    return true;
+  };
+
+  return processChunk;
+};