feat(mvp): phase 8 - integration, testing & deployment

Fix all build/type/lint errors (zod 3.25 compat wrapper, Svelte 5 fixes),
write 115 unit tests across 10 test files, expand seed script with demo
data, update Docker config with migration on startup.

src/lib/components/admin/PermissionEditor.svelte

@@ -117,7 +117,7 @@
 					class="w-full rounded border border-input bg-background px-2 py-1.5 text-sm text-foreground"
 				>
 					<option value="" disabled>Select...</option>
-					{#each entityOptions as option}
+					{#each entityOptions as option (option.id)}
 						<option value={option.id}>{option.name}</option>
 					{/each}
 				</select>
@@ -142,7 +142,7 @@
 					class="w-full rounded border border-input bg-background px-2 py-1.5 text-sm text-foreground"
 				>
 					<option value="" disabled>Select...</option>
-					{#each targetOptions as option}
+					{#each targetOptions as option (option.id)}
 						<option value={option.id}>{option.name}</option>
 					{/each}
 				</select>

src/lib/components/admin/SettingsForm.svelte

@@ -136,7 +136,7 @@
 				bind:value={$form.healthcheckDefaults}
 				rows="4"
 				class="w-full rounded-md border border-input bg-background px-3 py-2 font-mono text-sm text-foreground"
-				placeholder='{"interval": 300, "timeout": 5000, "method": "GET"}'
+				placeholder={'{"interval": 300, "timeout": 5000, "method": "GET"}'}
 			></textarea>
 			{#if $errors.healthcheckDefaults}<span class="text-xs text-destructive">{$errors.healthcheckDefaults}</span>{/if}
 		</div>

src/lib/components/admin/UserTable.svelte

@@ -104,7 +104,7 @@
 										class="rounded border border-input bg-background px-2 py-0.5 text-xs text-foreground"
 									>
 										<option value="" disabled>Select group</option>
-										{#each groups.filter((g) => !user.groups.some((ug) => ug.id === g.id)) as group}
+										{#each groups.filter((g) => !user.groups.some((ug) => ug.id === g.id)) as group (group.id)}
 											<option value={group.id}>{group.name}</option>
 										{/each}
 									</select>