feat(fase-11): settings tag management subsection (11.3.6)

Adds a "Tags" section to /settings between Collectives and Account. Lists
every tag in the active collective with:
  * inline rename — tap the chip, edit, Enter / blur to save
  * recolor swatch row (8 preset dots, current colour outlined)
  * delete button per tag (cascades item attachments via FK)

Uses the tagsStore which is already subscribed to item_tags realtime, so
edits from another tab / device update this view live without a reload.
No new screens; everything is inline in the existing settings layout.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/web/src/routes/(app)/settings/+page.svelte

@@ -9,6 +9,15 @@
 	import ImageCropper from '$lib/components/ImageCropper.svelte';
 	import ThemeToggle from '$lib/components/ThemeToggle.svelte';
 	import SyncConflictsPanel from '$lib/components/SyncConflictsPanel.svelte';
+	import TagChip from '$lib/components/TagChip.svelte';
+	import {
+		tags as tagsStore,
+		loadTags,
+		renameTag,
+		recolorTag,
+		deleteTag
+	} from '$lib/stores/tags';
+	import type { ItemTag, ItemTagColor } from '@colectivo/types';
 	import { languageTag, setLanguageTag } from '$lib/paraglide/runtime';
 	import * as m from '$lib/paraglide/messages';
 	import type { ThemePreference } from '$lib/theme';
@@ -43,8 +52,54 @@
 
 	onMount(async () => {
 		await loadProfile();
+		if ($currentCollective) {
+			await loadTags($currentCollective.id);
+		}
 	});
 
+	// Inline edit state for the tag list (one row at a time).
+	let editingTagId = $state<string | null>(null);
+	let editingTagName = $state('');
+	const TAG_COLORS: ItemTagColor[] = [
+		'slate',
+		'red',
+		'amber',
+		'green',
+		'sky',
+		'indigo',
+		'pink',
+		'stone'
+	];
+
+	function startEditTag(tag: ItemTag) {
+		editingTagId = tag.id;
+		editingTagName = tag.name;
+	}
+
+	async function commitEditTag() {
+		const id = editingTagId;
+		const next = editingTagName.trim();
+		editingTagId = null;
+		editingTagName = '';
+		if (id && next) {
+			await renameTag(id, next);
+		}
+	}
+
+	function cancelEditTag() {
+		editingTagId = null;
+		editingTagName = '';
+	}
+
+	async function handleRecolor(tag: ItemTag, color: ItemTagColor) {
+		if (tag.color === color) return;
+		await recolorTag(tag.id, color);
+	}
+
+	async function handleDeleteTag(id: string) {
+		await deleteTag(id);
+	}
+
 	async function loadProfile() {
 		if (!$currentUser) return;
 
@@ -397,6 +452,68 @@
 				{/if}
 			</section>
 
+			<!-- Tags (Fase 11.3.6) — collective-scoped tag management. Lives in
+			     settings because the tag flow on the list view is per-item; the
+			     full list of tags + rename + recolor + delete is admin-style. -->
+			<section data-testid="settings-tags-section" class="pt-8">
+				<p class="mb-3 text-[13px] font-semibold uppercase tracking-[0.05em] text-text-secondary">
+					{m.settings_tags_section()}
+				</p>
+				{#if $tagsStore.length === 0}
+					<p class="text-sm text-text-secondary">{m.settings_tags_empty()}</p>
+				{:else}
+					<ul class="space-y-2">
+						{#each $tagsStore as tag (tag.id)}
+							<li
+								data-testid="settings-tag-row"
+								data-tag={tag.name}
+								class="flex items-center gap-3 rounded-md bg-surface-raised px-3 py-2"
+							>
+								{#if editingTagId === tag.id}
+									<input
+										bind:value={editingTagName}
+										onblur={commitEditTag}
+										onkeydown={(e) => {
+											if (e.key === 'Enter') {
+												e.preventDefault();
+												void commitEditTag();
+											} else if (e.key === 'Escape') cancelEditTag();
+										}}
+										class="min-w-0 flex-1 rounded bg-background px-2 py-1 text-sm text-text-primary outline-none ring-1 ring-black/10 focus:ring-slate-900 dark:ring-white/10 dark:focus:ring-slate-100"
+									/>
+								{:else}
+									<button
+										type="button"
+										onclick={() => startEditTag(tag)}
+										class="min-w-0 flex-1 text-left"
+									>
+										<TagChip name={tag.name} color={tag.color} />
+									</button>
+								{/if}
+								<div class="flex shrink-0 items-center gap-1" aria-label={m.settings_tags_color()}>
+									{#each TAG_COLORS as color}
+										<button
+											type="button"
+											onclick={() => handleRecolor(tag, color)}
+											aria-label={color}
+											class="h-4 w-4 rounded-full bg-{color}-500 {tag.color === color ? 'ring-2 ring-offset-1 ring-slate-700 dark:ring-slate-300' : 'opacity-70 hover:opacity-100'}"
+										></button>
+									{/each}
+								</div>
+								<button
+									type="button"
+									data-testid="settings-tag-delete"
+									onclick={() => handleDeleteTag(tag.id)}
+									class="rounded-md border border-slate-300 px-2 py-1 text-xs font-medium text-slate-700 hover:bg-slate-50 dark:border-slate-600 dark:text-slate-300 dark:hover:bg-slate-800"
+								>
+									{m.settings_tags_delete()}
+								</button>
+							</li>
+						{/each}
+					</ul>
+				{/if}
+			</section>
+
 			<!-- Account — spacing creates the separation, not a border line -->
 			<section class="pt-8">
 				<p class="mb-3 text-[13px] font-semibold uppercase tracking-[0.05em] text-text-secondary">