Restructure nav to Load/Burn/Benchmark; fix SAA acpidump dependency

- Nav steps 3-5: Load (validate), Burn (burn-in), Benchmark (speed+endurance merged)
- /load now renders validate mode; /burn renders burn-in; /benchmark replaces /speed+/endurance
- Legacy redirects updated: /validate→/load, /burn-in→/burn, /speed+/endurance→/benchmark
- Add acpica_bin/acpidump from SAA 1.5.0 package; required by saa GetDmiInfo (ExitCode 8)
- build.sh copies acpica_bin/acpidump to /usr/local/bin/acpica_bin/ alongside saa

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/webui/page_validate.go

@@ -68,6 +68,14 @@ func validateTotalStressSec(n int) int {
 }
 
 func renderValidate(opts HandlerOptions) string {
+	return renderValidateMode(opts, false)
+}
+
+func renderValidateStress(opts HandlerOptions) string {
+	return renderValidateMode(opts, true)
+}
+
+func renderValidateMode(opts HandlerOptions, stressDefault bool) string {
 	inv := loadValidateInventory(opts)
 	n := inv.NvidiaGPUCount
 	validateTotalStr := validateFmtDur(validateTotalValidateSec(n))
@@ -76,7 +84,19 @@ func renderValidate(opts HandlerOptions) string {
 	if n > 0 {
 		gpuNote = fmt.Sprintf(" (%d GPU)", n)
 	}
-	return `<div class="alert alert-info" style="margin-bottom:16px"><strong>Non-destructive:</strong> Validate tests collect diagnostics only. They do not write to disks, do not run sustained load, and do not increment hardware wear counters.</div>
+	validateChecked, stressChecked := "checked", ""
+	if stressDefault {
+		validateChecked, stressChecked = "", "checked"
+	}
+	alert := `<div class="alert alert-info" style="margin-bottom:16px"><strong>Non-destructive:</strong> Validate tests collect diagnostics only. They do not write to disks, do not run sustained load, and do not increment hardware wear counters.</div>`
+	if stressDefault {
+		alert = `<div class="alert alert-warn" style="margin-bottom:16px"><strong>&#9888; Stress mode:</strong> Runs extended load tests — CPU stress-ng, memory passes, DCGM targeted diagnostics. Higher wear than Validate.</div>`
+	}
+	onloadJS := ""
+	if stressDefault {
+		onloadJS = `<script>satModeChanged();</script>`
+	}
+	return alert + `
 <p style="color:var(--muted);font-size:13px;margin-bottom:16px">Tasks continue in the background — view progress in <a href="/tasks">Tasks</a>.</p>
 
 	<div class="card" style="margin-bottom:16px">
@@ -84,8 +104,8 @@ func renderValidate(opts HandlerOptions) string {
 	  <div class="card-body validate-profile-body">
 	    <div class="validate-profile-col">
 	      <div class="form-row" style="margin:12px 0 0"><label>Mode</label></div>
-	      <label class="cb-row"><input type="radio" name="sat-mode" id="sat-mode-validate" value="validate" checked onchange="satModeChanged()"><span>Validate — quick non-destructive check</span></label>
-	      <label class="cb-row"><input type="radio" name="sat-mode" id="sat-mode-stress" value="stress" onchange="satModeChanged()"><span>Stress — thorough load test (` + stressTotalStr + gpuNote + `)</span></label>
+	      <label class="cb-row"><input type="radio" name="sat-mode" id="sat-mode-validate" value="validate" ` + validateChecked + ` onchange="satModeChanged()"><span>Validate — quick non-destructive check</span></label>
+	      <label class="cb-row"><input type="radio" name="sat-mode" id="sat-mode-stress" value="stress" ` + stressChecked + ` onchange="satModeChanged()"><span>Stress — thorough load test (` + stressTotalStr + gpuNote + `)</span></label>
 	    </div>
 	    <div class="validate-profile-col validate-profile-action">
 	      <p style="color:var(--muted);font-size:12px;margin:0 0 10px">Runs validate modules sequentially. Validate: ` + validateTotalStr + gpuNote + `; Stress: ` + stressTotalStr + gpuNote + `. Estimates are based on real log data and scale with GPU count.</p>
@@ -95,7 +115,7 @@ func renderValidate(opts HandlerOptions) string {
 	      </div>
 	    </div>
 	  </div>
-	</div>
+	</div>` + onloadJS
 
 <div class="grid3">
 ` + renderSATCard("cpu", "CPU", "runSAT('cpu')", "", renderValidateCardBody(
@@ -667,7 +687,7 @@ func renderCheck(opts HandlerOptions) string {
 	if n > 0 {
 		gpuNote = fmt.Sprintf(" (%d GPU)", n)
 	}
-	return `<div class="alert alert-info" style="margin-bottom:16px"><strong>Non-destructive:</strong> Check tests collect diagnostics only — no writes to disks, no sustained load, no hardware wear counters incremented. For stress testing, go to <a href="/load">3. Load</a>.</div>
+	return `<div class="alert alert-info" style="margin-bottom:16px"><strong>Non-destructive:</strong> Check tests collect diagnostics only — no writes to disks, no sustained load, no hardware wear counters incremented. For stress testing, go to <a href="/burn">4. Burn</a>.</div>
 <div style="display:flex;align-items:center;gap:12px;margin-bottom:16px">
   <button type="button" class="btn btn-primary" onclick="runAllCheckSAT()">Run All Checks</button>
   <span id="sat-all-status" style="font-size:12px;color:var(--muted)"></span>