Reduce host capacity headroom and remove learned usage padding

src/lib/server/hosts/calibration.ts

@@ -4,7 +4,6 @@ import type { CapacityCalibration, CapacitySample, CapacitySamplePage, HostInven
 
 const BOOTSTRAP_CPU = 0.5;
 const BOOTSTRAP_MEMORY = 1024 ** 3;
-const MARGIN = 1.25;
 const WINDOW_MS = 24 * 60 * 60_000;
 const MAX_SAMPLES = 10_000;
 type Phase = 'startup' | 'running';
@@ -83,8 +82,8 @@ export function recordInstanceResources(hostId: string, inventory: HostInventory
                 .all(...(scope === '*' ? [] : [scope]), phase, new Date(Date.parse(timestamp) - WINDOW_MS).toISOString(), MAX_SAMPLES) as
                 { cpu_cores: number; memory_bytes: number; bucket: string }[];
             const percentile = (values: number[]) => values.sort((a, b) => a - b)[phase === 'startup' ? values.length - 1 : Math.ceil(values.length * 0.95) - 1];
-            const cpu = Math.max(percentile(rows.map(row => row.cpu_cores)), peak.cpu) * MARGIN;
-            const memory = Math.ceil(Math.max(percentile(rows.map(row => row.memory_bytes)), peak.memory) * MARGIN);
+            const cpu = Math.max(percentile(rows.map(row => row.cpu_cores)), peak.cpu);
+            const memory = Math.ceil(Math.max(percentile(rows.map(row => row.memory_bytes)), peak.memory));
             handle.prepare(`INSERT INTO ec_resource_allowances
                 (scope,phase,cpu_cores,memory_bytes,samples,window_start,observed_at,computed_at) VALUES(?,?,?,?,?,?,?,?) ON CONFLICT(scope,phase) DO UPDATE SET
                 cpu_cores=excluded.cpu_cores,memory_bytes=excluded.memory_bytes,samples=excluded.samples,
@@ -96,7 +95,7 @@ export function recordInstanceResources(hostId: string, inventory: HostInventory
             // Raise the allowance immediately on a new peak; a lower sample
             // cannot reduce it until the next scheduled percentile calculation.
             handle.prepare(`UPDATE ec_resource_allowances SET cpu_cores=MAX(cpu_cores,?),memory_bytes=MAX(memory_bytes,?),observed_at=? WHERE scope=? AND phase=?`)
-                .run(peak.cpu * MARGIN, Math.ceil(peak.memory * MARGIN), timestamp, scope, phase);
+                .run(peak.cpu, Math.ceil(peak.memory), timestamp, scope, phase);
         }
     }
 }