Kernel messages (dmesg) source read from /dev/kmsg

New source in Settings > Sources, off by default: reads the kernel ring
buffer of the host through /dev/kmsg, dates records from the boot time and
resumes after the last sequence number of the same boot (no duplicates on
restart). Missing device or denied access is shown in the UI, retried every
10 s. docker-compose.yml and .env.example document the device and the
kernel.dmesg_restrict / CAP_SYSLOG options.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

web/index.html

@@ -102,6 +102,7 @@
       <option value="syslog">Syslog</option>
       <option value="docker">Docker</option>
       <option value="host" data-i18n="srcHost">Host system</option>
+      <option value="kernel" data-i18n="srcKernel">Kernel (dmesg)</option>
     </select>
     <span class="spacer"></span>
     <span id="count" class="muted"></span>
@@ -265,6 +266,16 @@
               <p class="muted small" data-i18n="hostHelp"></p>
             </section>
 
+            <section class="set-section">
+              <h3 data-i18n="dmesgTitle">Kernel messages (dmesg)</h3>
+              <p id="dmesgStatus" class="docker-status"></p>
+              <label class="switch-row">
+                <input id="dmesgEnabled" type="checkbox" class="switch">
+                <span data-i18n="dmesgEnabled">Collect the kernel messages of this machine</span>
+              </label>
+              <p class="muted small" data-i18n="dmesgHelp"></p>
+            </section>
+
             <section class="set-section span">
               <h3 data-i18n="dockerTitle">Docker containers</h3>
               <p id="dockerStatus" class="docker-status"></p>