Move fleet retention and concurrency controls into Settings

Persist settings in SQLite, import legacy environment values once, and apply changes to cleanup and deployment queues without restarting.

Closes #51

src/routes/api/settings/+server.ts

@@ -0,0 +1,12 @@
+import { json } from '@sveltejs/kit';
+import { validateFleetSettings } from '$lib/fleet-settings.js';
+import { fleetSettings, saveFleetSettings } from '$lib/server/settings.js';
+
+export function GET() { return json(fleetSettings()); }
+
+export async function PUT({ request }: { request: Request }) {
+    let settings;
+    try { settings = validateFleetSettings(await request.json()); }
+    catch (error) { return json({ error: (error as Error).message }, { status: 400 }); }
+    return json(saveFleetSettings(settings));
+}

src/routes/settings/+page.svelte

@@ -3,14 +3,71 @@
     import { availableTimeZones, DEFAULT_TIME_ZONE } from '$lib/time-zone.js';
     import { onMount } from 'svelte';
     import SectionHeader from '$ui/components/primitives/SectionHeader.svelte';
+    import Button from '$ui/components/primitives/Button.svelte';
+    import type { FleetSettings } from '$lib/fleet-settings.js';
     let exampleDate = $state<Date | null>(null);
+    let settings = $state<FleetSettings | null>(null);
+    let loading = $state(true);
+    let saving = $state(false);
+    let error = $state('');
+    let notice = $state('');
     const zones = $derived([...new Set([...availableTimeZones(), $timeZone])].sort());
-    onMount(() => { exampleDate = new Date(); });
+    onMount(() => { exampleDate = new Date(); void loadSettings(); });
+
+    async function loadSettings() {
+        loading = true; error = '';
+        try {
+            const response = await fetch('/api/settings');
+            if (!response.ok) throw new Error('Could not load fleet settings.');
+            settings = await response.json();
+        } catch (cause) { error = (cause as Error).message; }
+        finally { loading = false; }
+    }
+
+    async function saveSettings(event: SubmitEvent) {
+        event.preventDefault();
+        saving = true; error = ''; notice = '';
+        try {
+            const response = await fetch('/api/settings', { method: 'PUT', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(settings) });
+            const result = await response.json();
+            if (!response.ok) throw new Error(result.error ?? 'Could not save fleet settings.');
+            settings = result;
+            notice = 'Fleet settings saved. Changes apply to the next queue or cleanup check.';
+        } catch (cause) { error = (cause as Error).message; }
+        finally { saving = false; }
+    }
 </script>
 
 <svelte:head><title>Settings · Electric Cherry</title></svelte:head>
 <section class="page">
-    <SectionHeader title="Settings" subtitle="Choose how dates and times appear across Electric Cherry." />
+    <SectionHeader title="Settings" subtitle="Manage fleet limits, history retention, and display preferences." />
+    <section class="guide" aria-labelledby="fleet-heading">
+        <h2 id="fleet-heading">Fleet settings</h2>
+        <p>Saved for everyone using this Electric Cherry instance. Changes apply without restarting the app.</p>
+        {#if error}<p class="ui-error" role="alert">{error}</p>{/if}
+        {#if notice}<p role="status">{notice}</p>{/if}
+        {#if loading}
+            <p role="status">Loading fleet settings…</p>
+        {:else if settings}
+            <form onsubmit={saveSettings}>
+                <fieldset disabled={saving}>
+                    <label for="retention">Campaign history retention (days)</label>
+                    <input id="retention" type="number" min="1" max="36500" step="1" required bind:value={settings.deployKeepDays} aria-describedby="retention-help" />
+                    <p id="retention-help">Default: 7 days. Removes eligible old campaign records and file diffs on the next cleanup check. Pending, failed, held, and health-recovery-linked campaigns are kept. Provisioning history is retained.</p>
+                    <label for="restarts">Concurrent restarts</label>
+                    <input id="restarts" type="number" min="1" step="1" required bind:value={settings.restartConcurrency} aria-describedby="restarts-help" />
+                    <p id="restarts-help">Default: 1 across the fleet. Campaigns, betas, maintenance, and lifecycle actions share recovery slots until container and game health are verified.</p>
+                    <label for="startups">Concurrent server startups</label>
+                    <input id="startups" type="number" min="1" step="1" required bind:value={settings.createConcurrency} aria-describedby="startups-help" />
+                    <p id="startups-help">Default: 1 across collections and individual launches. Each startup holds its slot through container, game health, and selected-map verification.</p>
+                    <p>Lowering a limit lets active operations finish; queued work waits for capacity. Player safety checks still apply.</p>
+                    <Button type="submit" disabled={saving}>{saving ? 'Saving…' : 'Save fleet settings'}</Button>
+                </fieldset>
+            </form>
+        {:else}
+            <Button onclick={loadSettings}>Retry loading</Button>
+        {/if}
+    </section>
     <section class="guide" aria-labelledby="display-heading">
         <h2 id="display-heading">Display preferences</h2>
         <label class="timezone">Timezone
@@ -32,4 +89,7 @@
     p { font-size: var(--text-sm); color: var(--text-secondary); line-height: 1.65; }
     .timezone { display: grid; gap: 8px; margin-top: 16px; font-size: var(--text-sm); max-width: 420px; }
     .timezone select { width: 100%; padding: 10px 12px; font: inherit; color: var(--text-primary); background: var(--surface-sunken); border: 1px solid var(--border-control); border-radius: var(--radius-sm); }
+    fieldset { border: 0; padding: 0; margin: 20px 0 0; min-width: 0; }
+    fieldset label { display: block; margin: 20px 0 8px; font-size: var(--text-sm); }
+    fieldset input { width: 160px; padding: 10px 12px; font: inherit; color: var(--text-primary); background: var(--surface-sunken); border: 1px solid var(--border-control); border-radius: var(--radius-sm); }
 </style>