chansrv: Reconnect ibus when the cached connection has gone stale

Fixes #3230. The static `bus` global was only ever checked for
non-NULL, not for whether the underlying connection was still alive.
If ibus disconnected (daemon restart, stale socket) or the initial
connect attempt failed, `bus` was left set to a dead/freed connection,
so every later call to xrdp_input_unicode_init() took the "already
initialized" fast path and operated on it.

- Null out bus/g_engine in the "disconnected" signal handler instead
  of leaving them dangling after g_object_unref().
- Check ibus_bus_is_connected() before trusting a cached bus, and
  tear down + reconnect if it's stale.
- Unref and clear bus on a failed connect attempt instead of leaving
  it set.
- Guard the unrefs in xrdp_input_unicode_destroy() now that bus/
  g_engine can legitimately already be NULL.

.devcontainer/Dockerfile

@@ -1,100 +0,0 @@
-FROM ubuntu:24.04 AS builder
-
-# Pilot build against the xrdp/xorgxrdp "devel" branches (pre-0.11).
-# This is NOT the same codebase as Dockerfile (v0.10.x) - devel is ~787
-# commits / ~300 files ahead of v0.10.6.1, and xorgxrdp's devel branch has
-# moved together with it (137 commits / 81 files ahead of v0.10.5). Track
-# them as a pair; don't mix a devel xrdp with a tagged xorgxrdp or vice versa.
-#
-# Known deltas from the v0.10.x build baked into this file:
-#   - New hard dep: libxkbfile-dev (unconditional XKB header check)
-#   - --enable-ibus now also needs libibus-1.0-dev + libglib2.0-dev
-#   - NVENC support moved into a new helper binary (xrdp-accel-assist) that
-#     vendors its own NVENC API headers, so the nv-codec-headers clone/symlink
-#     step from the stable Dockerfile is gone - it's dead weight on devel.
-#   - --enable-accel is auto-derived from --enable-nvenc in configure.ac, so
-#     no new configure flag is needed to get xrdp-accel-assist built.
-#
-# devel is a floating branch, not a tag: Docker layer caching means a
-# `docker build` with no cache change will keep reusing an old clone.
-# Always pass --no-cache (or otherwise bust the git-clone layers) to actually
-# pick up new commits on each pilot run.
-#
-# Usage:
-#   docker build --no-cache -f Dockerfile.devel -t xrdp-builder:devel .
-#   docker run --rm -v $(pwd)/packages:/output xrdp-builder:devel
-
-# Get build and target platform info
-ARG TARGETPLATFORM
-ARG BUILDPLATFORM
-ARG TARGETARCH
-ARG TARGETVARIANT
-
-# Build arguments for versions - devel branches by default for this pilot
-ARG XRDP_VERSION=devel
-ARG XORGXRDP_VERSION=devel
-ARG PW_MODULE_XRDP_VERSION=devel
-
-# Prevent interactive prompts during build
-ENV DEBIAN_FRONTEND=noninteractive
-
-# Install build dependencies
-RUN apt-get update && apt-get install -y \
-    git \
-    autoconf \
-    automake \
-    libtool \
-    pkg-config \
-    gcc \
-    g++ \
-    make \
-    libssl-dev \
-    libpam0g-dev \
-    libx11-dev \
-    libxfixes-dev \
-    libxrandr-dev \
-    libxkbfile-dev \
-    nasm \
-    xsltproc \
-    flex \
-    bison \
-    libxml2-dev \
-    dpkg-dev \
-    libcap-dev \
-    libfuse3-dev \
-    libpixman-1-dev \
-    intltool \
-    xserver-xorg-dev \
-    xserver-xorg-core \
-    libconfig-dev \
-    libjpeg-dev \
-    wget \
-    libturbojpeg-dev \
-    libx264-dev \
-    libpulse-dev \
-    libopus-dev \
-    libibus-1.0-dev \
-    libglib2.0-dev \
-    ca-certificates \
-    libepoxy-dev \
-    libasound2-dev \
-    libdrm-dev \
-    libglvnd-dev \
-    libgbm-dev \
-    pipewire \
-    libpipewire-0.3-dev \
-    libspa-0.2-dev \
-    && rm -rf /var/lib/apt/lists/*
-
-RUN apt-get update && apt-get install -y \
-    nano \
-    xvfb \
-    xdotool \
-    ibus \
-    dbus-x11 \
-    openbox \
-    && rm -rf /var/lib/apt/lists/*
-
-# Match the workspaceFolder set in devcontainer.json
-WORKDIR /workspace
-CMD [ "tail", "-f", "/dev/null" ]

.devcontainer/devcontainer.json

@@ -1,29 +0,0 @@
-{
-  "$schema": "https://raw.githubusercontent.com/devcontainers/spec/main/schemas/devContainer.schema.json",
-  "name": "XRDP",
-  "build": { "dockerfile": "Dockerfile" },
-  "workspaceFolder": "/workspace",
-  "workspaceMount": "source=${localWorkspaceFolder},target=/workspace,type=bind",
-  "remoteUser": "root",
-  "mounts": [
-  {
-    "source": "${localEnv:HOME}${localEnv:USERPROFILE}/.claude",
-    "target": "/root/.claude",
-    "type": "bind",
-    "consistency": "cached"
-  },
-  {
-    "source": "${localEnv:HOME}${localEnv:USERPROFILE}/.gitconfig",
-    "target": "/root/.gitconfig",
-    "type": "bind",
-    "consistency": "cached"
-  },
-  {
-    "source": "${localEnv:HOME}${localEnv:USERPROFILE}/.git-credentials",
-    "target": "/root/.git-credentials",
-    "type": "bind",
-    "consistency": "cached"
-  }
-
-]
-}