Promote as a real deployment; version state and scope dropdowns

Turns promotion into a first-class deployment (action='promote') so it lands
in the deployments UI with before/after content, per-server restart tracking,
and one-click rollback. Non-beta matching-scope servers get restart_state=
pending so the existing sweep drains and restarts them the same way drift does.

Also adds a per-version state (untested/tested/test-failed) so the upload
flow can visibly signal that a beta must land before promotion, and swaps
the scope-value text box for game/map dropdowns populated from the fleet.
Beta rollback at ready-promote is now labelled Reject and marks the version
test-failed.

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

src/routes/betas/[id]/+page.svelte

@@ -75,7 +75,11 @@
         } finally { acting = null; }
     }
     async function rollback(): Promise<void> {
-        if (!confirm('Rollback this beta?')) return;
+        const isReject = beta?.state === 'ready-promote';
+        const prompt = isReject
+            ? `Reject beta #${id}? This restores original files on every beta server and marks the version as test-failed.`
+            : `Rollback beta #${id}? This restores original files on every beta server.`;
+        if (!confirm(prompt)) return;
         acting = 'rollback';
         flash = null;
         try {
@@ -171,7 +175,13 @@
                 onclick={rollback}
                 disabled={beta.state === 'promoted' || beta.state === 'rolled-back' || acting !== null}
             >
-                {acting === 'rollback' ? 'rolling back…' : 'rollback'}
+                {#if acting === 'rollback'}
+                    {beta.state === 'ready-promote' ? 'rejecting…' : 'rolling back…'}
+                {:else if beta.state === 'ready-promote'}
+                    reject
+                {:else}
+                    rollback
+                {/if}
             </button>
         </div>
     </section>