feat(optimize): add Phase 2 power profile and system tuning

Add `make optimize-power` (ryzenadj 85W, sysctl, THP, RADV nogttspill)
with systemd services for boot/resume persistence. Integrate into
`make optimize --all` as Phase 2. Update optimization log with RyzenAdj
results (+46% tg at 70W sustained), KV sweep data, and quant shootout.
Add Qwen3-Coder-30B and Nemotron-Cascade-2 to model catalog.

scripts/optimize/power-profile.sh

@@ -0,0 +1,111 @@
+#!/usr/bin/env bash
+# Apply power profile and system tuning for LLM inference workloads
+# Requires root. Settings are volatile — use the systemd service for persistence.
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/../../lib/common.sh"
+source "$SCRIPT_DIR/../../lib/format.sh"
+
+require_root
+
+# ── Power limits via ryzenadj ─────────────────────────────
+STAPM=85000
+FAST=85000
+SLOW=85000
+APU_SLOW=85000
+
+if is_cmd ryzenadj; then
+    log_header "Power Profile (ryzenadj)"
+    log_info "Setting STAPM=${STAPM}mW, Fast=${FAST}mW, Slow=${SLOW}mW, APU=${APU_SLOW}mW"
+    ryzenadj \
+        --stapm-limit=$STAPM \
+        --fast-limit=$FAST \
+        --slow-limit=$SLOW \
+        --apu-slow-limit=$APU_SLOW 2>&1 | grep -E 'Successfully|Error|not supported' || true
+
+    # Verify what actually took effect
+    log_info "Verifying limits..."
+    ryzenadj -i 2>&1 | grep -E 'LIMIT|VALUE' | head -8
+    echo ""
+    log_warn "Note: HP firmware may cap PPT SLOW/APU at 70W regardless of setting"
+else
+    log_error "ryzenadj not found. Install: cd /tmp && git clone https://github.com/FlyGoat/RyzenAdj.git && cd RyzenAdj && mkdir build && cd build && cmake .. && make && sudo cp ryzenadj /usr/local/bin/"
+    exit 1
+fi
+
+# ── VM sysctl tuning ──────────────────────────────────────
+log_header "VM Sysctl Tuning"
+
+declare -A SYSCTLS=(
+    [vm.swappiness]=1
+    [vm.dirty_ratio]=40
+    [vm.dirty_background_ratio]=10
+    [vm.max_map_count]=500000
+    [vm.zone_reclaim_mode]=0
+)
+
+for KEY in "${!SYSCTLS[@]}"; do
+    VAL="${SYSCTLS[$KEY]}"
+    CURRENT=$(sysctl -n "$KEY" 2>/dev/null || echo "?")
+    if [[ "$CURRENT" == "$VAL" ]]; then
+        log_success "$KEY = $VAL (already set)"
+    else
+        sysctl -w "$KEY=$VAL" > /dev/null 2>&1
+        log_success "$KEY = $VAL (was $CURRENT)"
+    fi
+done
+
+# Persist sysctl settings
+SYSCTL_CONF="/etc/sysctl.d/99-llm-inference.conf"
+if [[ ! -f "$SYSCTL_CONF" ]]; then
+    log_info "Persisting to $SYSCTL_CONF"
+    cat > "$SYSCTL_CONF" << 'EOF'
+# LLM inference optimizations
+vm.swappiness = 1
+vm.dirty_ratio = 40
+vm.dirty_background_ratio = 10
+vm.max_map_count = 500000
+vm.zone_reclaim_mode = 0
+EOF
+    log_success "Sysctl config saved (persists across reboots)"
+else
+    log_info "Sysctl config already exists at $SYSCTL_CONF"
+fi
+
+# ── Transparent Huge Pages ────────────────────────────────
+log_header "Transparent Huge Pages"
+
+THP_ENABLED=$(cat /sys/kernel/mm/transparent_hugepage/enabled 2>/dev/null || echo "unknown")
+if [[ "$THP_ENABLED" == *"[always]"* ]]; then
+    log_success "THP = always (already set)"
+else
+    echo always > /sys/kernel/mm/transparent_hugepage/enabled 2>/dev/null || true
+    echo defer+madvise > /sys/kernel/mm/transparent_hugepage/defrag 2>/dev/null || true
+    log_success "THP = always, defrag = defer+madvise"
+fi
+log_info "For persistence, add to kernel cmdline: transparent_hugepage=always"
+
+# ── RADV nogttspill ───────────────────────────────────────
+log_header "Vulkan RADV Environment"
+
+RADV_CONF="/etc/environment.d/radv-llm.conf"
+if [[ ! -f "$RADV_CONF" ]]; then
+    mkdir -p /etc/environment.d
+    echo 'RADV_PERFTEST=nogttspill' > "$RADV_CONF"
+    log_success "RADV_PERFTEST=nogttspill persisted to $RADV_CONF"
+    log_info "Takes effect on next login. For this session: export RADV_PERFTEST=nogttspill"
+else
+    log_success "RADV config already exists at $RADV_CONF"
+fi
+
+# ── Summary ───────────────────────────────────────────────
+log_header "Phase 2 Optimization Summary"
+log_success "Power profile: ryzenadj limits applied (volatile — resets on reboot)"
+log_success "VM tuning: sysctl applied and persisted"
+log_success "THP: enabled (volatile — add to kernel cmdline for persistence)"
+log_success "RADV: nogttspill persisted"
+echo ""
+log_info "To persist ryzenadj across reboots:"
+log_info "  sudo cp $SCRIPT_DIR/../../configs/ryzenadj-llm.service /etc/systemd/system/"
+log_info "  sudo systemctl enable --now ryzenadj-llm.service"