feat(tags): Generate tags button + chip-based tag editor

Generate tags mirrors Generate summary: reads the transcript (the same
build_prompt assembly, non-streamed) and suggests 1-8 tags, merged
into the working tag list rather than replacing it outright so a
manually-added tag never silently disappears.

Replaces the old comma-separated text input with GitHub-topic-style
chips: typing a comma commits everything before it as its own chip
immediately, each chip is removable via its 'x', and clicking a chip's
label filters the meeting list to that tag (meetings.filterByTag).

src/lib/views/SummaryPanel.svelte

@@ -4,8 +4,15 @@
   import { meetings } from "../stores/meetings.svelte";
   import { calendar } from "../stores/calendar.svelte";
   import { settings } from "../stores/settings.svelte";
-  import { api, type ActionItem, type CalendarEventDetail, type LlmStatus } from "../api";
+  import {
+    api,
+    errorMessage,
+    type ActionItem,
+    type CalendarEventDetail,
+    type LlmStatus,
+  } from "../api";
   import { renderMarkdown } from "../markdown";
+  import TagChip from "../components/TagChip.svelte";
   import {
     Tags,
     Sparkles,
@@ -150,24 +157,79 @@
   }
 
   // ---- Tags (T8.3, FR-SEARCH-2) ----
-  // Writable derived: reflects meetings.selected.tags, but typing (bind:value)
-  // locally overrides it until the selection changes again.
-  let tagsInput = $derived((meetings.selected?.tags ?? []).join(", "));
+  // pendingTags is the editable working copy — resynced from
+  // meetings.selected.tags whenever a *different* meeting is selected, same
+  // guard pattern as notesText in TranscriptNotes.svelte, so it isn't
+  // clobbered by other reactivity while the user is mid-edit.
+  let pendingTags = $state<string[]>([]);
+  let tagDraft = $state("");
+  let loadedTagsForId: string | null = null;
+  $effect(() => {
+    const m = meetings.selected;
+    if (m && m.id !== loadedTagsForId) {
+      pendingTags = [...m.tags];
+      tagDraft = "";
+      loadedTagsForId = m.id;
+    } else if (!m) {
+      loadedTagsForId = null;
+    }
+  });
+
+  function addTag(raw: string) {
+    const t = raw.trim().toLowerCase();
+    if (t && !pendingTags.includes(t)) pendingTags.push(t);
+  }
+  // GitHub-topics-style input: a comma commits everything before it as its
+  // own chip immediately, leaving whatever's after as the live draft.
+  function onTagInput() {
+    if (!tagDraft.includes(",")) return;
+    const parts = tagDraft.split(",");
+    tagDraft = parts.pop() ?? "";
+    parts.forEach(addTag);
+  }
+  function onTagInputKeydown(e: KeyboardEvent) {
+    if (e.key === "Enter") {
+      e.preventDefault();
+      commitDraft();
+    }
+  }
+  function commitDraft() {
+    if (tagDraft.trim()) addTag(tagDraft);
+    tagDraft = "";
+  }
+  function removeTag(t: string) {
+    pendingTags = pendingTags.filter((x) => x !== t);
+  }
+
   let savingTags = $state(false);
   async function saveTags() {
     const m = meetings.selected;
     if (!m) return;
+    commitDraft();
     savingTags = true;
     try {
-      const tags = tagsInput
-        .split(",")
-        .map((t) => t.trim())
-        .filter(Boolean);
-      await meetings.setTags(m.id, tags);
+      await meetings.setTags(m.id, pendingTags);
     } finally {
       savingTags = false;
     }
   }
+
+  let generatingTags = $state(false);
+  let tagGenError = $state<string | null>(null);
+  async function generateTagsNow() {
+    const m = meetings.selected;
+    if (!m) return;
+    generatingTags = true;
+    tagGenError = null;
+    try {
+      const suggested = await api.generateTags(m.id);
+      suggested.forEach(addTag);
+    } catch (e) {
+      tagGenError = errorMessage(e);
+    } finally {
+      generatingTags = false;
+    }
+  }
 </script>
 
 <div class="wrap">
@@ -214,21 +276,42 @@
   {#if !meetings.selected}
     <p class="muted">Select a meeting to tag it.</p>
   {:else}
-    <input
-      class="grow"
-      list="known-tags"
-      placeholder="project, client, topic…"
-      bind:value={tagsInput}
-      onkeydown={(e) => e.key === "Enter" && saveTags()}
-    />
+    <div class="tag-editor">
+      {#each pendingTags as t (t)}
+        <TagChip
+          tag={t}
+          removable
+          onRemove={() => removeTag(t)}
+          onClick={() => meetings.filterByTag(t)}
+        />
+      {/each}
+      <input
+        class="tag-input"
+        list="known-tags"
+        placeholder={pendingTags.length ? "Add tag…" : "project, client, topic…"}
+        bind:value={tagDraft}
+        oninput={onTagInput}
+        onkeydown={onTagInputKeydown}
+        onblur={commitDraft}
+      />
+    </div>
     <datalist id="known-tags">
       {#each meetings.allTags as t (t)}
         <option value={t}></option>
       {/each}
     </datalist>
-    <button class="link" onclick={saveTags} disabled={savingTags}>
-      {savingTags ? "Saving…" : "Save tags"}
-    </button>
+    <div class="actions">
+      <button class="primary" onclick={generateTagsNow} disabled={generatingTags}>
+        <Sparkles size={14} aria-hidden="true" />
+        {generatingTags ? "Generating…" : "Generate tags"}
+      </button>
+      <button class="link" onclick={saveTags} disabled={savingTags}>
+        {savingTags ? "Saving…" : "Save tags"}
+      </button>
+    </div>
+    {#if tagGenError}
+      <p class="error">{tagGenError}</p>
+    {/if}
   {/if}
 
   <h3><Sparkles size={14} aria-hidden="true" /> Summary</h3>
@@ -435,6 +518,30 @@
     font-size: 0.85rem;
     margin: 0;
   }
+  .tag-editor {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.35rem;
+    padding: 0.3rem 0;
+  }
+  .tag-input {
+    flex: 1;
+    min-width: 6rem;
+    border: none;
+    background: none;
+    padding: 0.2rem 0;
+    font-size: 0.8rem;
+  }
+  .tag-input:focus {
+    outline: none;
+  }
+  .actions {
+    display: flex;
+    align-items: center;
+    gap: 0.7rem;
+    margin-top: 0.4rem;
+  }
   .muted.small {
     font-size: 0.78rem;
   }