feat: filter and search by tag

internal/web/templates/metadata.tmpl

@@ -11,9 +11,12 @@
     </form>
     <div class="meta-tags">
       {{ range .Note.Tags }}
-      <form method="POST" action="/notes/{{ $.Note.ID }}/tags/{{ . }}" class="tag-remove-form">
-        <button type="submit" class="tag">{{ . }} ×</button>
-      </form>
+      <span class="tag-chip">
+        <a class="tag-link" href="/?tag={{ . | urlquery }}">{{ . }}</a>
+        <form method="POST" action="/notes/{{ $.Note.ID }}/tags/{{ . | urlquery }}" class="tag-remove-form">
+          <button type="submit" class="tag-remove" aria-label="Remove tag {{ . }}">×</button>
+        </form>
+      </span>
       {{ end }}
     </div>
   </section>

internal/web/templates/noteList.tmpl

@@ -23,6 +23,7 @@
 
 {{ define "renderSearch" }}
 {{ if ne .SearchTerm "" }}<h2>Matching results for query '{{ .SearchTerm }}'</h2>{{ end }}
+{{ if ne .TagFilter "" }}<h2>Filtered by tag '{{ .TagFilter }}'</h2>{{ end }}
   <ul class="search-results">
     {{ range .Notes }}
     <li {{ if eq .ID $.LastActive }}class="active-note"{{ end }}>