feat: rename service to galo, add halo branding and release build

- rename Go module, binary, systemd unit, PG_DATABASE default, frontend package and docs from shared-album to galo
- add theme-aware halo emblem and favicon (new ui-branding capability)
- add make build-release (versioned, stripped, static binary) and run the binary from the repo root

frontend/src/lib/components/Emblem.svelte

@@ -0,0 +1,28 @@
+<script lang="ts">
+	interface Props {
+		label?: string;
+		class?: string;
+	}
+
+	let { label, class: className = 'size-5' }: Props = $props();
+</script>
+
+<svg
+	viewBox="0 0 64 64"
+	class={className}
+	role={label ? 'img' : undefined}
+	aria-label={label}
+	aria-hidden={label ? undefined : 'true'}
+	focusable="false"
+>
+	<circle cx="32" cy="32" r="13" fill="currentColor" />
+	<circle
+		cx="32"
+		cy="32"
+		r="24"
+		fill="none"
+		stroke="currentColor"
+		stroke-width="6"
+		stroke-opacity="0.45"
+	/>
+</svg>