Two-digit code per color tag, shown as badges on matching log lines

Each tag gets a stable code (01-99) assigned by the server and stored in
tags.json; existing tags get one when the file is loaded. A fixed-width
Filters column shows the codes of the active tags found in each message
(room for 3, then 2 + "+N", all listed in the tooltip).

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

web/index.html

@@ -107,6 +107,7 @@
       <span data-col="sev"><span class="lbl" data-i18n="colSev">Severity</span><i class="grip" data-i18n-title="colGrip"></i></span>
       <span data-col="host"><span class="lbl" data-i18n="colHost">Host</span><i class="grip" data-i18n-title="colGrip"></i></span>
       <span data-col="app"><span class="lbl" data-i18n="colApp">App</span><i class="grip" data-i18n-title="colGrip"></i></span>
+      <span data-col="codes"><span class="lbl" data-i18n="colCodes" data-i18n-title="codesTitle">Filters</span></span>
       <span data-col="msg"><span class="lbl" data-i18n="colMsg">Message</span></span>
     </div>
     <main id="list" class="list"></main>